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 Travel_Word_Problems/636394: a gun is fired from a distance of 1.2 km from a hill . The echo of the sound is heard back at the same place after 8 seconds find the velocity of sound?? 1 solutions Answer 400991 by ankor@dixie-net.com(15649)   on 2012-08-10 15:44:13 (Show Source): You can put this solution on YOUR website!a gun is fired from a distance of 1.2 km from a hill . The echo of the sound is heard back at the same place after 8 seconds find the velocity of sound?? : change 1.2 km to 1200 meters, round trip will be 2400 meters = 300 m/sec is the speed of sound
 Surface-area/636358: I have a 10ft in diameter oval pool If I build a 3 ft walkway around it what is the square footage of the walkway? the answer and how to figure it out thank you 1 solutions Answer 400988 by ankor@dixie-net.com(15649)   on 2012-08-10 15:35:55 (Show Source): You can put this solution on YOUR website!I have a 10ft in diameter oval pool If I build a 3 ft walkway around it what is the square footage of the walkway? : The overall diameter, including the walkway, will be 16 ft, then overall radius = 8 ft, (pool radius = 5 ft) : Walkway area = overall area - pool area ww.a = - ww.a = 122.522 sq/ft
 Mixture_Word_Problems/636254: A solution of 61% bleach is to be mixed with a solution of 27% bleach to make 68 gallons of a 44% solution. How many gallons of each should be used? 1 solutions Answer 400967 by ankor@dixie-net.com(15649)   on 2012-08-10 14:23:35 (Show Source): You can put this solution on YOUR website!A solution of 61% bleach is to be mixed with a solution of 27% bleach to make 68 gallons of a 44% solution. How many gallons of each should be used? : Let x = amt of 61% bleach required the resulting mixture is to be 68 gal, therefore: (68-x) = amt of 27% solution required : A typical mixture equation : .61x + .27(68-x) = .44(68) : .61x + 18.36 - .27x = 29.92 .61x - .27x = 29.92 - 18.36 .34x = 11.56 x = 11.56/.34 x = 34 gal of 61% solution and 68 - 34 = 34 gal of 27% solution
 Linear_Equations_And_Systems_Word_Problems/636231: An 8 dm by 6 dm picture is to be photocopied in reduced size. The owner wants the copy to be half the size of the original picture. If the length and the width of the original picture will be reduced by the same measure, find the dimension of the photocopy.1 solutions Answer 400942 by ankor@dixie-net.com(15649)   on 2012-08-10 13:09:51 (Show Source): You can put this solution on YOUR website!An 8 dm by 6 dm picture is to be photocopied in reduced size. The owner wants the copy to be half the size of the original picture. If the length and the width of the original picture will be reduced by the same measure, find the dimension of the photocopy. : Find the area of the original: 8 * 6 = 48 sq/dm Assume half the size means half the area: 24 sq/dm Let x = amt of reduction in the length and width : (8-x)*(6-x) = 24 48 - 8x - 6x + x^2 = 24 : Arrange as a quadratic equation x^2 - 14x + 48 - 24 = 0 x^2 - 14x + 24 = 0 : Factors to (x-2)(x-12) = 0 : Two solution but x = 2 dm reduction is the only reasonable solution : new dimensions 6 by 4 Check (8-2) * (6-2) = 24
 Travel_Word_Problems/636314: If the voltage in an electric circuit is held constant, the current I is inversely proportional to the resistance R. If the current is 40 amperes when the resistance is 270 ohms, find the current when the resistance is 150 ohms. 1 solutions Answer 400934 by ankor@dixie-net.com(15649)   on 2012-08-10 12:53:50 (Show Source): You can put this solution on YOUR website!If the voltage in an electric circuit is held constant, the current I is inversely proportional to the resistance R. If the current is 40 amperes when the resistance is 270 ohms, find the current when the resistance is 150 ohms. : Ohm's law for finding the voltage; E = I*R E = 40 * 270 E = 10,800 volts : Ohm's law for finding the current I = E/R I = I = 72 amps
 Age_Word_Problems/636144: grandmother Alice says my daughter Mary is 26 years younger than me and 34 years older than my granddaughter Lisa if you add all of our ages together the total is 100 how old are Alice Mary and Lisa1 solutions Answer 400839 by ankor@dixie-net.com(15649)   on 2012-08-09 21:47:13 (Show Source): You can put this solution on YOUR website! grandmother Alice says my daughter Mary is 26 years younger than me and 34 years older than my granddaughter Lisa if you add all of our ages together the total is 100 how old are Alice Mary and Lisa : Write three equations from the information given here : A = M + 26 L = M - 34 A + M + L = 100 : In the last equation replace A with (M+26); replace L with (M-34), find M (M+26) + M + (M-34) = 100 3M - 8 = 100 3M = 108 M = 108/3 M = 36 yrs is Mary's age : You should be able to find A and L, ensure they add up to 100
 Travel_Word_Problems/636006: A boat travel straight down a river at a speed of 15 m/sec. If the boat travels a distance of 34.1 km, how long was the boat ride?1 solutions Answer 400818 by ankor@dixie-net.com(15649)   on 2012-08-09 18:55:14 (Show Source): You can put this solution on YOUR website!A boat travel straight down a river at a speed of 15 m/sec. If the boat travels a distance of 34.1 km, how long was the boat ride? : Change 34.1 km to meter 34.1 * 1000 = 34,100 meters : Time = dist/speed : t = = 2273.33 seconds Change seconds to minutes = 37.9 minute boat ride
 Rational-functions/636126: 19. One high-speed jet travels 100 miles per hour faster than another. When one plane travels 2000 miles, the other travels 1500 miles. Find the speed of each plane. Thanks so much in advance for your help1 solutions Answer 400797 by ankor@dixie-net.com(15649)   on 2012-08-09 17:36:25 (Show Source): You can put this solution on YOUR website!One high-speed jet travels 100 miles per hour faster than another. When one plane travels 2000 miles, the other travels 1500 miles. Find the speed of each plane. : Let s = speed of the slower plane then (s+100) = speed of the faster : Write a time equation: time = dist/speed : = Cross multiply, find s
 Travel_Word_Problems/636112: Two runners start running at the same time from start/finish line of a 400 meter oval track. One runner runs laps of 1 minute 15 seconds and the other runner runs laps of 1 minute 45 seconds. HOw long will it be before the runners cross the start/finish line at the smae time? How many laps will each have run?1 solutions Answer 400771 by ankor@dixie-net.com(15649)   on 2012-08-09 16:10:18 (Show Source): You can put this solution on YOUR website!Two runners start running at the same time from start/finish line of a 400 meter oval track. One runner runs laps of 1 minute 15 seconds and the other runner runs laps of 1 minute 45 seconds. How long will it be before the runners cross the start/finish line at the same time? How many laps will each have run? : Change 1 min 15 min to 75 sec; and 1 min 45 sec to 105 sec Find least common multiple of 75 and 105 using prime factors 75: 3*5*5 105: 3*5*7 LCM: 3*5*5*7 = 525 sec which is 525/60 = 8.75 min, which is: 8 min 45 sec when both runners cross the finish line at the same time then One runner completes exactly 525/75 = 7 laps and Other runner completes exactly 525/105 = 5 laps
 Travel_Word_Problems/636128: a car covers the first half of the distance between two places at a speed of 40km/hr and second half at 60 km/hr . calculate the average speed of the car1 solutions Answer 400755 by ankor@dixie-net.com(15649)   on 2012-08-09 15:30:57 (Show Source): You can put this solution on YOUR website!a car covers the first half of the distance between two places at a speed of 40km/hr and second half at 60 km/hr . calculate the average speed of the car : let a = average speed for the trip let d = half the distance : write a time equation, time = dist/speed + = we don't need d, divide thru by d and you have + = multiply by 120a to clear the denominators, results: 3a + 2a = 120(2) 5a = 240 a = 240/5 a = 48 km/hr
 Equations/636124: x=√(42 - x)1 solutions Answer 400750 by ankor@dixie-net.com(15649)   on 2012-08-09 15:18:18 (Show Source): You can put this solution on YOUR website!x=√(42 - x) square both sides x^2 = 42 - x Arrange as a quadratic equation x^2 + x - 42 = 0 Factors to (x+7)(x-6) = 0 Two solutions x = -7 x = 6, this is the only valid solution
 Age_Word_Problems/635990: my current age is 4 times what my sisters age was 20 years ago. i am now twice as old as i was 20 years ago. ten years ago, my sisters age was 1/2 of my current age. ten years ago, my age was 1.5 times my sisters age. what are our current ages?1 solutions Answer 400747 by ankor@dixie-net.com(15649)   on 2012-08-09 15:12:31 (Show Source): You can put this solution on YOUR website!Let y = your current age Let s = sister's current age : Write an equation for each statement, simplify as much as possible: : "my current age is 4 times what my sisters age was 20 years ago." y = 4(s-20) y = 4s - 80 : " I am now twice as old as i was 20 years ago." y = 2(y-20) y = 2y - 40 40 = 2y -y y = 40 yr, your present age : Right here you know enough to solve this 40 = 4s - 80 40 + 80 = 4s s = 120/4 s = 30 is the sisters age : You can check this using the rest of the equations with y=40, s=30 : ten years ago, my sisters age was 1/2 of my current age. " s - 10 = .5y multiply both sides by 2 2(s-10) = y 2s - 20 = y : "ten years ago, my age was 1.5 times my sisters age." y - 10 = 1.5(s-10) y - 10 = 1.5s - 15 y = 1.5s - 15 + 10 y = 1.5s - 5 : Two unknowns, two equations are sufficient. :
 Quadratic_Equations/636085: x+2/3 + x-1/4 = 3/21 solutions Answer 400743 by ankor@dixie-net.com(15649)   on 2012-08-09 14:55:40 (Show Source): You can put this solution on YOUR website!Assume the problem is: + = multiply by 12 (LCM) to clear the denominators 12* + 12* = 12* Cancel out the denominators 4(x+2) + 3(x-1) = 6(3) : 4x + 8 + 3x - 3 = 18 7x + 5 = 18 7x = 18 - 5 7x = 13 x =
 test/636101: How to solve radical equations with radicals on both sides1 solutions Answer 400737 by ankor@dixie-net.com(15649)   on 2012-08-09 14:14:36 (Show Source): You can put this solution on YOUR website!How to solve radical equations with radicals on both sides : If there is just a single radical term on each side (no other terms) just square both sides. If there is another term, you square it, by the FOIL method, and it becomes a lengthy process. : You will do better on this site to submit an actual problem, asking for a step-by-step method to solve it.
 Equations/636030: I need to make a solution of 20% alcohol. I have on hand 98% alcohol. What is the ratio of 98% alcohol and sterile water to make 20% alcohol?1 solutions Answer 400735 by ankor@dixie-net.com(15649)   on 2012-08-09 14:07:09 (Show Source): You can put this solution on YOUR website!make a solution of 20% alcohol. I have on hand 98% alcohol. What is the ratio of 98% alcohol and sterile water to make 20% alcohol? : Decide how much of the 20% solution you require, let's say 10 liters Let w = amt of water required then (10-w) = amt of 98% alcohol required : .98(10-w) = .20w 9.8 - .98w = .20w 9.8 = .20w + .98w 9.8 = 1.18w w = 9.8/1.18 w ~ 8.3 liters of water and 10 - 8.3 = 1.7 liters of the 98% solution : if you need a ratio; water: 98% alcohol:
 Numbers_Word_Problems/635740: The sum of the digit of a three digit number is 12.If the digits are reversed the number are increased by 495 but reversing only of the ten’s and unit digits increases the number by 36.The number is:1 solutions Answer 400720 by ankor@dixie-net.com(15649)   on 2012-08-09 13:13:59 (Show Source): You can put this solution on YOUR website!The sum of the digit of a three digit number is 12. If the digits are reversed the number are increased by 495 but reversing only of the ten’s and unit digits increases the number by 36. The number is: : Let a = 100's digit Let b = 10's digit Let c = the units Then 100a + 10b + c = "the number" : Write an equation for each statement, combine and simplify: : "The sum of the digit of a three digit number is 12." a + b + c = 12 : "If the digits are reversed the number are increased by 495" 100a + 10b + c = 100c + 10b + a - 495 100a - a + 10b - 10b = 100c - c - 495 99a = 99c - 495 divide thru by 99 a = c - 5 : "but reversing only of the ten’s and unit digits increases the number by 36." 100a + 10b + c = 100a +10c + b - 36 100a - 100a + 10b - b = 10c - c - 36 9b = 9c - 36 simplify, divide by 9 b = c - 4 : Back to the 1st equation a + b + c = 12 replace a with (c-5); replace b with (c-4) c-5 + (c-4) + c = 12 3c - 9 = 12 3c = 12 + 9 3c = 21 c = 21/3 c = 7 : You should be able to find a and b, and create the original number
 Surface-area/635684: An old fence used to enclose a circular lot is to be recycled to fence a square lot. If the radius of the circular lot is 5 meters, how long should the edge of the square lot be?1 solutions Answer 400607 by ankor@dixie-net.com(15649)   on 2012-08-08 19:29:25 (Show Source): You can put this solution on YOUR website!An old fence used to enclose a circular lot is to be recycled to fence a square lot. If the radius of the circular lot is 5 meters, how long should the edge of the square lot be? : Let s = side of the square then 4s = the perimeter of the square : the perimeter of the square lot = the circumference of the circular lot : 4s = : s = s = 7.854 meters
 Mixture_Word_Problems/635848: How much pure water must be mixed with 10 liters of a 25% acid solution to reduce it to a 10% acid solution?1 solutions Answer 400604 by ankor@dixie-net.com(15649)   on 2012-08-08 19:22:04 (Show Source): You can put this solution on YOUR website!How much pure water must be mixed with 10 liters of a 25% acid solution to reduce it to a 10% acid solution? : let w = amt of water required to accomplish this : The amt of acid will remain the same only the water will increase, lowering the percent : .25(10) = .10(w+10) 2.5 = .10w + 1 2.5 - 1 = .1w 1.5 = .1w w = w = 15 liters of water : : Confirm this .25(10) = .10(25)
 Age_Word_Problems/635690: The age of a father was 6 times the age of his son two years ago. After six years the ratio of their ages was 10:3. what is the age of father now?1 solutions Answer 400601 by ankor@dixie-net.com(15649)   on 2012-08-08 19:15:15 (Show Source): You can put this solution on YOUR website!The age of a father was 6 times the age of his son two years ago. After six years the ratio of their ages was 10:3. what is the age of father now? : Let f = father's present age let s = son's age : "The age of a father was 6 times the age of his son two years ago." f - 2 = 6(s - 2) f - 2 = 6s - 12 f = 6s - 12 + 2 f = 6s - 10 : "After six years the ratio of their ages was 10:3." = cross multiply 10(s+6) = 3(f+6) 10s + 60 = 3f + 18 10s + 60 - 18 = 3f 10s + 42 = 3f Replace f with (6s-10) 10s + 42 = 3(6s-10) 10s + 42 = 18s - 30 42 + 30 = 18s - 10s 72 = 8s s = 72/8 s = 9 yrs is the son's age then f = 6s - 10 f = 6(9) - 10 f = 54 - 10 f = 44 yrs is the father's age : : : Confirm that = =
 Polynomials-and-rational-expressions/635783: Explain, in complete sentences, how to factor 4x2 – 4x – 48. Explain how your factors could be checked for accuracy1 solutions Answer 400560 by ankor@dixie-net.com(15649)   on 2012-08-08 15:24:42 (Show Source): You can put this solution on YOUR website!factor 4x^2 – 4x – 48. factor out 4 in each of the three terms 4(x^2 - x - 12) Find the factors of 12 which differ by 1, -x means the larger factor will be neg 4(x-4)(x+3) : You can confirm this by FOILing (x-4)(x+3) and multiplying that by 4
 Travel_Word_Problems/635715: A bullet is fired at a target and the sound its impact is heard 6 seconds later. If it travels at the rate of 2200 feet per second and sound travels at the rate of 1100 feet per second, how far away is the target? 1 solutions Answer 400559 by ankor@dixie-net.com(15649)   on 2012-08-08 15:13:39 (Show Source): You can put this solution on YOUR website!A bullet is fired at a target and the sound its impact is heard 6 seconds later. If it travels at the rate of 2200 feet per second and sound travels at the rate of 1100 feet per second, how far away is the target? : Let d = distance to the target : Write a time equation: time = dist/speed : bullet time + impact sound time = 6 seconds + = 6 multiply by 2200 2200* + 2200* = 2200*6 cancel out denominators, and you have d + 2d = 13200 3d = 13200 d = 13200/3 d = 4400 ft to the target : : confirm this, find the time each way 4400/2200 = 2 sec 4400/1100 = 4 sec ------------------ total time: 6 sec
 Travel_Word_Problems/635388: A man rides up a ski lift at the rate of 5 miles an hour and skis back down the hill at the rate of 50 miles an hour. If the complete trip requires 22 minutes, How far is it from the bottom to the top of the hill?1 solutions Answer 400420 by ankor@dixie-net.com(15649)   on 2012-08-07 21:51:22 (Show Source): You can put this solution on YOUR website!A man rides up a ski lift at the rate of 5 miles an hour and skis back the hill at the rate of 50 miles an hour. If the complete trip requires 22 minutes How far is it from the bottom to the top of the hill? : Change 22 minutes to hrs, hrs : Let d = distance up the hill (assume down the hill is the same) : Write a time equation: time = dist/speed Time up + time down = 22 min + = Mult by the LCM; 300 300* + 300* = 300* cancel the denominators 60d + 6d = 5(22) 66d = 110 d = d = 1 miles bottom to top of the hill : : Check this find the time each way 1.67/5 = .3340 hrs 1.67/50= .0334 hrs -------------------- total time: .3674 hrs which is .3674(60) = 22.0 min
 Travel_Word_Problems/635338: David participates in a bicycle race in which a rider starts every 5 minutes. David's average is 33 km/hr. After 28 minutes, he is overtaken by a rider who started 2 persons after him. What is the rate of the other cyclist in km/hr?1 solutions Answer 400390 by ankor@dixie-net.com(15649)   on 2012-08-07 18:03:09 (Show Source): You can put this solution on YOUR website!David participates in a bicycle race in which a rider starts every 5 minutes. David's average is 33 km/hr. After 28 minutes, he is overtaken by a rider who started 2 persons after him. What is the rate of the other cyclist in km/hr? : Let s = speed of the 2nd cyclist : From the information given, the 2nd rider started 15 min behind David : Change 28 min to hrs: hrs, David's travel time Change (28-15) = hrs, 2nd rider's travel time : When this happens, they will have traveled the same distance. Write a distance equation; dist = speed * time : s = (33) multiply both sides by 60 13s = 28(33) 13s = 924 s = 924/13 s = 71.1 km/hr, speed of the 2nd rider : : Confirm this by finding the distance of each *71.1 = 15.4 km *33 = 15.4 km
 Angles/635270: If I have a triangle... Angle 1 is 20 degrees, angle 2 is 90 and angle 3 is unknown. Side C is 10 feet, the other two sides are x and y. Solve for x and y. Here is a drawing: http://twitpic.com/agc8gm Thank you!1 solutions Answer 400239 by ankor@dixie-net.com(15649)   on 2012-08-06 21:29:43 (Show Source): You can put this solution on YOUR website!a triangle... Angle 1 is 20 degrees, angle 2 is 90 and angle 3 is unknown. Side C is 10 feet, the other two sides are x and y. Solve for x and y. : Sin(20) = ; (side opposite/hypotenuse) .342x = 10 x = 10/.342 x = 29.238 ft : Tan(20) = ; (side opposite/side adjacent .364y = 10 y = 10/.364 ft y = 27.475
 Travel_Word_Problems/635156: if it took vehicle A 114 miles per hour to catch up to vehicle B on a 4 mile stretch. How fast was vehicle B going if both vehicles were 500 feet apart?1 solutions Answer 400236 by ankor@dixie-net.com(15649)   on 2012-08-06 20:52:27 (Show Source): You can put this solution on YOUR website!if it took vehicle A 114 miles per hour to catch up to vehicle B on a 4 mile stretch. How fast was vehicle B going if both vehicles were 500 feet apart? : let b = vehicle B's speed in ft/sec : Find how long for vehicle A to cover 4 miles * 3600 = 126.3 seconds : Find how many ft/sec at 114 mph = 167.2 ft/sec : A has to overtake vehicle B in 126.3 sec = 126.3 500 = 126.3(167.2-b) 500 = 21117.36 - 126.3b 126.3b = 21117.36 - 500 126.3b = 20617.36 b = 20617.36/126.2 b = 163.24 ft/sec, speed of the car B Change speed to mph = 111.3 mph speed of B :
 Pythagorean-theorem/635117: I need help. I do not understand any of this. I need to build or generate at least five more Pythagorean Triples using one of the many formulas available. After building your triples, verify each of them in the Pythagorean Theorem equation. The assignment must include (a) all math work required to answer the problems as well as (b) introduction and conclusion paragraphs. Thank you for any help you can give me.1 solutions Answer 400165 by ankor@dixie-net.com(15649)   on 2012-08-06 15:43:58 (Show Source): You can put this solution on YOUR website!generate at least five more Pythagorean Triples using one of the many formulas available. After building your triples, verify each of them in the Pythagorean Theorem equation. : Euclid's formula for generating triples, given an arbitrary pair of positive integers, m and n, where m > n. a^2 + b^2 = c^2 a = m^2 - n^2 b = 2mn c = m^2 + n^2 : Choose numbers less than 10 Example1; m=3, n=2 a = 3^2 - 2^2 = 9 - 4 = 5 b = 2(3*2) = 12 c = 3^2 + 2^2 = 13 So we have a triple: 5, 12, 13 5^2 + 12^2 = 13^2 25 + 144 = 169 : Example 2: m=7, n=3 a = 49-9 = 40 b = 2(7*3) = 42 c = 49 + 9 = 58 a=40, b=42, c=58 : Example 3: m=9, m=5 a = 81 - 25 = 56 b = 2(9*5) = 90 c = 81 + 25 = 106 a=56, b=90, c = 106 : You should be able to generate a few more using this method, check them on your calc enter: to find c
 Travel_Word_Problems/635043: Karen traveled 640 miles by boat and returned by plane. She spent 42 hours traveling on the trip. If the rate of the plane is 20 times faster than the rate of the boat, find each rate.1 solutions Answer 400048 by ankor@dixie-net.com(15649)   on 2012-08-05 21:59:42 (Show Source): You can put this solution on YOUR website!Karen traveled 640 miles by boat and returned by plane. She spent 42 hours traveling on the trip. If the rate of the plane is 20 times faster than the rate of the boat, find each rate. : Let r = speed of the boat then 20r = speed of the plane : Write a time equation; time = dist/speed : boat time + plane time = 42 hrs + = 42 reduce the fraction, divide 20 into 640 + = 42 = 42 42r = 672 r = 672/42 r = 16 mph, boat speed then 20(16) = 320 mph is the plane speed : : Confirm this find the travel time of each 640/16 = 40 hrs 640/320 = 2 hrs ----------------- totals: 42 hrs
 Complex_Numbers/634980: (2-5i)^21 solutions Answer 400047 by ankor@dixie-net.com(15649)   on 2012-08-05 21:39:46 (Show Source): You can put this solution on YOUR website!(2-5i)^2 FOIL (2-5i)(2-5i) 4 - 10i - 10i + 25i^2 4 - 20i + 25(-1) 4 - 20i - 25 = -21 - 20i
 Angles/635012: if two angles are supplementary and one angle is 11 times as big as the other angle, find the measure of the larger angle. 1 solutions Answer 400046 by ankor@dixie-net.com(15649)   on 2012-08-05 21:29:24 (Show Source): You can put this solution on YOUR website!if two angles are supplementary and one angle is 11 times as big as the other angle, find the measure of the larger angle. : Let x = one angle then 11x = the larger angle : Supplementary, means the two angles add up to 180 x + 11x = 180 12x = 180 x = 180/12 x = 15 degrees is the small angle 11(15) = 165 degrees is the larger angle
 Inequalities/634883: Are the conditions- a+b+c>0 & abc>0, sufficient to say that a>0,b>0,c>0 is ab+bc+ca>0 required in addition to conclude that a>0,b>0,c>0. please explain in detail. 1 solutions Answer 400018 by ankor@dixie-net.com(15649)   on 2012-08-05 16:28:02 (Show Source): You can put this solution on YOUR website!Are the conditions- a+b+c>0 & abc>0, sufficient to say that a>0,b>0,c>0 No, two could be neg and their sum less than the positive number For example: a=8, b=-2, c=-3, 8-5 > 0 and 8*-2*-3 = 40 >0 : ab+bc+ca>0 required in addition to conclude that a>0,b>0,c>0. No. Actually if all the numbers are neg, it would be >0
 Numbers_Word_Problems/634772: If five times a number is subtracted from twelve times a number, the result is seven less than twice the number. Find the number.1 solutions Answer 400014 by ankor@dixie-net.com(15649)   on 2012-08-05 16:15:56 (Show Source): You can put this solution on YOUR website!If five times a number is subtracted from twelve times a number, the result is seven less than twice the number. Find the number. : Let n = the number : 12n - 5n = 2n - 7 12n - 5n - 2n = -7 5n =-7 n = n = -1.4 is the number : : See if that checks out 12(-1.4) - 5(-1.4) = 2(-1.4) - 7 -16.8 + 7 = -2.8 - 7 -9.8 = -9.8