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checkley71 answered: 8399 problems
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obtain a grade of C. His first three test grades were 75, 63, and 68. Write an inequality
representing the score that Sam must get on the last test to get a C grade.
1 solutions
Answer 36918 by checkley71(8403) on 2006-10-04 19:05:16 (Show Source):
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Linear-systems/54689: 1.12x + 1.08y = 0
x+y = 500
No clue where to start. Please help. 1 solutions
Answer 36915 by checkley71(8403) on 2006-10-04 18:50:14 (Show Source):
You can put this solution on YOUR website!X+Y=500 OR X=500-Y NOW SUBSTITUTE (500-Y) FOR X IN EQUATION #1
WE GET 1.12(500-Y)+1.08Y=0
560-1.12Y+1.08Y=0
-.04Y=-560
Y=-560/-.04
Y=14,000 THEN
X+14,000=500
X=500-14,000
X=-13,500
PROOF
1.12(-13,500)+1.08*14,000=0
-15,120+15,120=0
0=0
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Expressions-with-variables/54685: This question is from textbook
To be honest I am not sure what category it is. Can you please help me, I only know the first steps? Please read everything that I worte. It's only one problem, I just have a few quetions and I hope you can explain it clearly enought to me. Thank You for the help!The section of my book says "Solving Equations with variables on Both Sides" The problem is....
9(b-4)-7b=5(3b-2)
9b-36-7b=15b-2
this is where I kinda get confused, do you minus 9b from 9b then minus 9b from 7b or do you add 7b to 7b then add 7b to 9b. Can you do -36-2? Can you tell me what some of these steps are and why it is what it is please? For this problem I only know how to combine like terms and do the little division thing at the end. I can do easier problems like 12y+21=9y , 12y-12y+21=9y-12y, 21=-3y. -3y divided by -3 cancels out then you do it to the other side 21 divided by -3 = -7 so y=-7 1 solutions
Answer 36911 by checkley71(8403) on 2006-10-04 18:43:22 (Show Source):
You can put this solution on YOUR website!9(B-4)-7B=5(3B-2)
9B-36-7B=15B-10
9B-7B-15B=36-10
-13B=26
B=26/-13
B=-2
PROOF
9(-2-4)-7(-2)=5(3[-2]-2)
9(-6)+14=5(-6-2)
-54+14=5(-8)
-40=-40
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Mixture_Word_Problems/54690: a football player carried the ball 5 times during a game. he gained 15 yards on the first play, gained 11 yards on the third carry, lost 9 yards on the fourth and had no gain or loss on the fifth carry. what was his total amount of yardage for the game? 1 solutions
Answer 36910 by checkley71(8403) on 2006-10-04 18:28:50 (Show Source):
You can put this solution on YOUR website!CAN'T CALCULATE THE TOTAL UARDAGE BECAUSE THERE IS NO MENTION OF THE SECOND CARRY. THE OTHER 4 CARRIES ACOOUNT FOR 15+?+11-9+0=17+? YARDS WITHOUT THE SECOND CARRY.
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Linear-systems/54683: Solve the following equation by elimination.
x+y = 500
0.09x+20 = .11y
No clue where to start please help. 1 solutions
Answer 36909 by checkley71(8403) on 2006-10-04 18:24:11 (Show Source):
You can put this solution on YOUR website!IN ORDER TO ELIMINATE ONE VARIABLE WE NEED TO MULTIPLY THE FIRST EQUATION BY
-.09 TO ELIMINATE THE X VARIABLE THUS
-.09X+-09Y=-45
.09X-.11Y=-20 NOW WE CAN ADD THESE TWO EQUATION
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-.2Y=-65 OR Y=-65/-.2 OR Y=325 & X+325=500 OR X=500-325 OR X=175
PROOF .09*175+20=.11*325 OR 15.75+20=35.75 OR 35.75=35.75
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Linear-systems/54681: A principal of $2500 is invested; part at 8% per annum and the rest at 12% per annum. In one year, the two investments earned equal amounts of interest. How much was invested at each rate? 1 solutions
Answer 36908 by checkley71(8403) on 2006-10-04 18:15:18 (Show Source):
You can put this solution on YOUR website!.12*x=.08(2500-x) or .12x=200-.08x or .2x=200 or x=200/.2 or x=1000 thus
$1,000*.12=$120 & .08*(2500-1000) or .08*1500=120 thus the interest for both investments are $120.
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Triangles/54589: how do you find the area of a triangle when the only given number is 5 1 solutions
Answer 36863 by checkley71(8403) on 2006-10-04 11:37:10 (Show Source):
You can put this solution on YOUR website!YOU CAN ONLY FIND THE AREA OF A TRIANGLE GIVEN ONE SIDE OF THE TRIANGLE IS 5 -- IF THE TRIANGLE IS AN EQUILATERAL TRIANGLE (ALL SIDES ARE EQUAL)
THEN THE AREA IS A=(1/2)B*H. THE H IS FOUND BY SOLVING THE EQUATION A^2+B^2=C^2 AND WE HAVE ONE SIDE=5/2 OR 2.5 (SIDE A OR B) AND C=5 THUS
5^2=2.5^+B^2 OR 25=6.25+B^2 OR 25-6.25-B^2 OR B^2=18.75 OR B=SQRT18.75
OR 4.33 = THE HEIGHT OF THE TRIANGLE THUS THE AREA A=(1/2)5*4.33 OR
A=21.65/2 OR A=10.825
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Surface-area/54607: This question is from textbook Integrated mathematics
find the length of the side of a rhombus whose diagonals measure 6 centimeters and 8 centimeters. 1 solutions
Answer 36862 by checkley71(8403) on 2006-10-04 11:25:31 (Show Source):
You can put this solution on YOUR website!A RHOMBUS IS A 4 EQUALLY SIDED FIGURE. DIAGONALS OF A RHOMBUS FORM RIGHT ANGLES. THUS THE DIAGONALS FORM 4 EQUAL RIGHT ANGLE TRIANGLES WITH THE INNER SIDES EQUAL TO 1/2 THE DIAGONALS. THUS THE SMALLER SIDES OF THESE TRIANGLES ARE 3 & 4 CENTIMETERS. THUS THE RIGHT TRIANGLE IS A^2=B^2=C62 OR 3^2+4^4=C^2 OR 9+16=C62 OR C=5 THUS THE HYPOTENUSE OF THESE 4 EQUAL TRIANGLES IS 5 CENTIMETERS. SEEING AS ALL SIDES ARE EQUAL IN A RHOMBUS THEN ALL SIDES ARE 5 CENTIMETERS.
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Exponential-and-logarithmic-functions/54615: Please help w/ the following: Thank you
The amount of money A accured at the end of N years when a certain amount P is invested at a compound annual rate r is given by A=P(1+r)^n. If a person invests $160 at 4% interest compounded annually, find the approximate amount obtained at the end of 15 years. 1 solutions
Answer 36860 by checkley71(8403) on 2006-10-04 11:10:22 (Show Source):
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Travel_Word_Problems/54610: A plane took 1 hour longer to travel 560 miles on the first portion of a flight than it took to fly 480 miles on the second portion. If the speed was the same for each portion, what was the flying time for the second part of the trip?
When I worked out the problem I came up with 5 hours and then 6 hours the second time. Please help! 1 solutions
Answer 36858 by checkley71(8403) on 2006-10-04 11:01:52 (Show Source):
You can put this solution on YOUR website!SEEING THE FORMULA FOR THIS TYPE OF PROBLEM IS DISTANCE=SPEED*TIME
D=S*T OR S=560/(T+1) & S=480/T THEN 560/(T+1)=480/T OR 560T=480T+480 OR
80T=480 OR T=480/80 OR T=6 HOURS THUS THE SPEED IS S=560/(6+1) OR S=560/7 OR
S=80 MPH & S=480/6 OR S=80 MPH FOR BOTH LEGS OF THE FLIGHT.THE FIRST LEG TAKING 7 HOURS & THE LAST LEG TAKING 6 HOURS FOR A TOTAL OF 13 HOURS FOR THE 1040 MILE FLIGHT OR 1040=80*13 OR 1040=1040
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Systems-of-equations/54566: Can someone help me solve this problem?
I need to complete the ordered pairs so that each is a solution for the given equation: 3x + 4y = 12
pair 1 is (0,)
Pair 2 is (, 3/4)
pair 3 is (,0)
pair 4 is (8/3,)
Thanks,
Sher 1 solutions
Answer 36821 by checkley71(8403) on 2006-10-03 22:59:24 (Show Source):
You can put this solution on YOUR website!(0,3) just substitute the given value x=0 & solve for y
(3,3/4) just substitute the given value y=3/4 & solve for x
(4,0)
(8/3,1)
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Expressions-with-variables/54558: Admission to a national park is so much per van. A group of friends in a van shared the admission cost by paying $0.50 apiece. If 2 more friends had joined them, everyone would have paid on $0.40 apiece. How much does it cost a van to enter the park? 1 solutions
Answer 36818 by checkley71(8403) on 2006-10-03 22:27:35 (Show Source):
You can put this solution on YOUR website!X(.50)=(X+2).40 OR .50X=.40X+.80 OR (.50-.40)X=.80 OR .1X=.80 OR X=.80/.1 OR
X=8.00 IS THE NUMBER OF PEOPLE PAYING $.50 THUS THE TOTAL PRICE FOR THE VAN IS 8*.50 OR $4.00 THUS (8+2).40=$4.00 IF 10 PEOPLE EACH PAY $.40
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Expressions-with-variables/54559: One number is 3 more than half of a second number. If the average of the two numbers is 15 1/2, find the smaller of the two numbers. 1 solutions
Answer 36817 by checkley71(8403) on 2006-10-03 22:20:20 (Show Source):
You can put this solution on YOUR website!(X+Y)/2=15.5 THEN X+Y=31 OR X=31-Y AND X=3+Y/2 THUS 31-Y=3+Y/2 OR Y+Y/2=31-3 OR
3/2Y=28 OR 3Y=28*2 OR 3Y=56 OR Y=18 2/3 THEN X=31-18/2/3 OR X=12 1/3 [THE SMALLER NUMBER]
PROOF 18 2/3+12 1/3=31 OR 31=31 AND 12 1/3=3+(18 2/3)/2 OR 12 1/3=3+9 1/3 OR
12 1/3=12 1/3
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Linear_Equations_And_Systems_Word_Problems/54545: i get so confused when i work with fraction can someone please assist.
Solve each equation by the subtraction method. Determine whether the equation are independent, dependant, or inconsistent. Solve each system by the addition method
3/7x + 5/9y = 27
1/9x + 2/7y = 7 1 solutions
Answer 36809 by checkley71(8403) on 2006-10-03 22:03:16 (Show Source):
You can put this solution on YOUR website!TO SOLVE BY THE SUBTRACTION METHOD YOU NEED TO BE ABLE TO ELIMINATE ONE OF THE VARIABLES THUS MULTIPLY THE FIRST EQUATION BY 1/9 & MULTIPLY THE SECOND EQUATION BY -3/7 THIS RESULTS IN THE FOLLOWING EQUATONS:
(1/9)(3/7)X+(1/9)(5/9)Y=(1/9)27 &
(-3/7)(1/9)X+(-3/7)(2/7)=(-3/7)7 NOW WE ADD THESE TWO EQUATIONS
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0X+(5/81)Y+(6/49)Y=3-3 OR Y(5/81)+(6/49)=0 OR Y=0
SUBSTITUTING Y=0 IN EITHER EQUATION WE SOLVE FOR X THUS
(3/7)X+0=27 OR 3X=27*7 OR 3X=189 OR X=63
PROOF USING THE OTHER EQUATION WE GET
(1/9)63=7 OR 63/9=7 OR 7=7
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absolute-value/54551: This question is from textbook Algebra 1 concepts and skills
what is the slope-intercept form of the equation of the line whose x-intercept is 3 and whose y-intercept is 5? 1 solutions
Answer 36807 by checkley71(8403) on 2006-10-03 21:48:25 (Show Source):
You can put this solution on YOUR website!AN X INTERCEPT OF 3 IS DEFINED BY THE POINT(3,0) & THE Y INTERCEPT OF 5 IS DEFINED BY THE POINT(0,5).
NOW WE FIND THE SLOPE (5-0)/(0-3)=5/-3 OR THE SLOPE IS -5/3
NOW WE USE THE LINE EQUATION Y=mX+b WHERE THE m VALUE IS THE SLOPE AND THE b VALUE IS THE Y INTERCEPT POINT SO WE HAVE Y=-5/3X+5
TO PROVE WE HAVE THE CORRECT EQUATION YOU CAN SUBSTITUTE EITHER SET OF X&Y VALUES IN THIS EQUATION AND SOLE IT. THUS
0=-5/3*3+5 OR 0=115/3-5 OR 0=-5+5 OR 0=0
5=-5/3*0+5 OR 5=0+5 OR 5=5
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Square-cubic-other-roots/54504: I am stuck on correct answer for:
If Y = 2X and 3X - 3Y = 2, then X =
I am not using any specific book. I am just practicing... 1 solutions
Answer 36752 by checkley71(8403) on 2006-10-03 18:17:06 (Show Source):
You can put this solution on YOUR website!IF Y=2X & 3X-3Y=2 THEN 3X-3(2X)=2 OR 3X-6X=2 OR -3X=2 OR -X=2/3 OR X=-2/3 THEN
Y=2(-2/3) OR Y=-4/3
PROOF 3(-2/3)-3(-4/3)=2 OR -6/3+12/3=2 OR -2+4=2 OR 2=2
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NO!!!!!!!! X=-2/3 & Y=-4/3
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Equations/54485: Im working on Equations with variables on both sides and my teacher wants me to write down all the steps, but I cant even figure out where to start. The problem is
25u+74=23u+92 all I know is first I add like 25u and 23u but then i dont get it. 1 solutions
Answer 36743 by checkley71(8403) on 2006-10-03 17:26:21 (Show Source):
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Expressions-with-variables/54486: At 10:00 a.m, a car leaves a house at a rate of 60 mi/h. At the same time, another car leaves the same house at a rate of 50 mi/h in the opposite direction. At what time will the cars be 330 miles apart? 1 solutions
Answer 36741 by checkley71(8403) on 2006-10-03 17:21:50 (Show Source):
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Exponents/54484: What is the difference between negative numbers in parenthesis with an exponent outside the parenthesis and a negative number with an exponent with no parenthesis ?
(-2)^2
or
-2^2 1 solutions
Answer 36736 by checkley71(8403) on 2006-10-03 16:59:07 (Show Source):
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Quadratic_Equations/54429: A lawn(rectangular shape is to have an area of 86M.Forty metres of timber edging is available to complaetely edge the lawn.determine the lawn length and width so that all timber edging is used 1 solutions
Answer 36687 by checkley71(8403) on 2006-10-03 07:07:36 (Show Source):
You can put this solution on YOUR website!X*Y=86 & 2X+2Y=40 THUS 2X=40-2Y OR X=20-Y THEN SUBSTITUTE (20-Y) FOR X IN THE FIRST EQUATION WE GET (20-Y)Y=86 OR 20Y-Y^2-86=0 OR -Y^2+20Y-86=0 OR
Y^2-20Y+86=0 USING THE QUADRATIC EQUATION (-B+/-SQRT(B^2-4AC))/2A WE GET ANSWERS OF:
-10+/-SQRT14 OR 13.7442 & 6.258
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