Tutors Answer Your Questions about Systemsofequations (FREE)
Question 993472: The sum of two numbers is 66. Their difference is 8.
Write in system of equations
Can someone help me please
Found 2 solutions by MathTherapy, rothauserc: Answer by MathTherapy(4047) (Show Source):
You can put this solution on YOUR website! The sum of two numbers is 66. Their difference is 8.
Write in system of equations
Can someone help me please
Let larger number be L, and smaller, S
We then get:
Add the 2 equations to ELIMINATE S, and to determine L, the larger number
Substitute the value for L in any of the 2 equations to find the value of S, the smaller number
Answer by rothauserc(2272) (Show Source):
You can put this solution on YOUR website! x + y = 66
x  y = 8
*******************************************
solve second equation for x
x = y + 8
substitute for x in first equation
y+8 +y = 66
2y = 58
y = 29
*******************************************
x  29 = 8
x = 37
******************************************
x = 37 and y = 29
Question 993214: A boat travels 48 miles upstream in 6 hours. Going down stream it can travel 72 miles in the same amount of tume. Find the speed of the current and speed of the boat in still water
Answer by lwsshak3(11500) (Show Source):
You can put this solution on YOUR website! A boat travels 48 miles upstream in 6 hours. Going down stream it can travel 72 miles in the same amount of tume. Find the speed of the current and speed of the boat in still water
let x=speed of boat in still water
let c=speed of current
(x+c)=speed of boat downstream
(xc)=speed of boat upstream
travel time*speed=distance
6*(x+c)=72
6*(xc)=48
6x+6c=72
6x6c=48
12x=120
x=10
6c=7260
6c=12
c=2
speed of boat in still water=10 mph
let c=speed of current=2 mph
Question 992662: F varies directly with m and inversely with the square of D
If F=150 when m=240 and d=8, find F when m=360 and d=3.
Answer by rothauserc(2272) (Show Source):
You can put this solution on YOUR website! we use k as the constant of proportionality, then
F = mk / d^2
we are given F = 150, m = 240, d = 8
150 = 240k / 8^2
240k = 9600
k = 40
*************************************
our formula becomes
F = 40m / d^2
we are given m=360, d= 3
F = (40*360) / 3^2
F = 1600
Question 992514: A=r/2L solve for L
Answer by Timnewman(249) (Show Source):
Question 992073: 2y+6xy=z. solve for y
Answer by jim_thompson5910(33401) (Show Source):
Question 991036: Write the verbal translation of the formula
For converting temperature from Celsius (C) to Fahrenheit (F) which is F=5/9C+32
Answer by Cromlix(3061) (Show Source):
You can put this solution on YOUR website! Hi there,
The Celsius reading.
Multiply this value by 9.
Finally divide the answer by 5.
Add 32 to reading.
°C x 9/5 + 32 = °F
Hope this helps. :)
Question 990196: What's the solution to 5x+2y=10 and 3x6y=18
Answer by Fombitz(25151) (Show Source):
Question 990395: Formulate a system of equations for the situation below and solve.
A theater has a seating capacity of 834 and charges $3 for children, $5 for students, and $7 for adults. At a certain screening with full attendance, there were half as many adults as children and students combined. The receipts totaled $4346. How many children attended the show?
Answer by macston(4006) (Show Source):
You can put this solution on YOUR website! .
C=number of children. S=number of students, A=number of adults
.
(1/2)(C+S)=A
C+S=2A Use this to substitute for (C+S)
.
C+S+A=834
(C+S)+A=834 Substitute for (C+S)
2A+A=834
3A=834
A=278 .
278 Adults attended the show.
Receipts from adults=($7)(278)=$1946
Receipts from students and children=$4346$1946=$2400
.
C+S=834278
C+S=556
C=556S Use this to substitute for C
.
$3C+$5S=$2400 Substitute for C.
$3(556S)+$5S=$2400
$1668$3S+$5S=$2400
$2S=$732
S=366
366 Students attended the show.
.
C=556S=556366=190
ANSWER: 190 children attended the show.
.
CHECK:
C+S+A=834
190+366+278=834
834=834
.
$3C+$5S+$7A=$4346
$3(190)+$5(366)+$7(278)=$4346
$570+$1830+$1946=$4346
$4346=$4346
.
Question 990344: 2x+y=5,3x+2y=8
Answer by stanbon(69061) (Show Source):
You can put this solution on YOUR website! 2x+y=5
3x+2y=8

Modify for elimination:
4x + 2y = 10
3x + 2y = 8

Subtract and solve for "y"::
x = 2

Solve for "y"::
2x + y = 5
4 + y = 5
y = 1

Cheers,
Stan H.

Question 990349: 6a+3b=4,a+b=1
Answer by Boreal(1464) (Show Source):
Question 990114: 13 + x = 25
Answer by jim_thompson5910(33401) (Show Source):
Question 989339: Certain chemotherapy dosages depend on a patient's surface area. According to the Mosteller model
S = √(h*M) / 6
where h is the patient's height in m, M is the patient's mass in kg and S is the patient's approximate surface area in m^2. Assume that the patient's height is a constant 187 cm but he is on a diet. If a patient loses 3.1 kg per month, how fast is his surface area changing (in m^2/month) at the instant his mass is 71 kg?
Give your answer correct to 4 decimal places.
Note. You may be wondering why we have referred to the patient's mass here, rather than his weight. Technically, a person's weight is a force (recall: F = Ma, where F is the force, M is the mass, and a is the acceleration, which in this case is g, the acceleration due to gravity). Force (and therefore weight) is measured in Newtons, not kilograms. Scientists, and you are one, should know that. (In orbit, an astronaut experiences weightlessness, not masslessness.)  I am not sure why this matters?
I am so confused!
Initial = S = √(187*71) / 6 = 19.2043
After One month = S = √(187*69.7) / 6 = 19.0277
I am not sure how to put these together?
THANK YOU
Found 2 solutions by jim_thompson5910, MathLover1: Answer by jim_thompson5910(33401) (Show Source): Answer by MathLover1(11324) (Show Source):
Question 988745: 8(9)
Answer by jim_thompson5910(33401) (Show Source):
Question 988534: 4x+y=14 and y=3x solution
Answer by macston(4006) (Show Source):
You can put this solution on YOUR website! .
y=3x Use this to substitute for y
.
4x+y=14 Substitute for y
4x+3x=14
7x=14
x=2
.
y=3x Put in value for x
y=3(2)
y=6
.
ANSWER: (2,6)
.
CHECK:
4x+y=14
4(2)+6=14
8+6=14
14=14
Question 988444: 6(a+8)
Answer by jim_thompson5910(33401) (Show Source):
You can put this solution on YOUR website! Multiply the outer 6 by each term inside. So 6 times 'a' is 6a. Also, 6 times +8 is 48
In the end, 6(a+8) distributes to 6a48
Question 988348: place the number 19 in the squares so that none of the rows, columns, or diagonals have the same sum. Plz help
Answer by solver91311(20879) (Show Source):
Question 988350: joey dumped the change out of his pocket and found that he had 25 coins totaling exactly $1.00 what coins might joey have had in his pocket? Plz help
Answer by solver91311(20879) (Show Source):
You can put this solution on YOUR website!
First thing to note is that you must have some pennies. That is because if you had all nickels, you would only have 20 coins.
Second, you must have a number of pennies that is divisible by 5, because if you have some number of pennies NOT divisible by 5, you can't get to an even dollar no matter how many coins you have.
Third, you can't have as many as 25 pennies, because that would account for all 25 coins, but you only have 25 cents.
So, let's examine the situation if you have 20 pennies. That means that you would have to make 80 cents from 5 coins consisting of quarters, dimes, and nickels.
Is it possible to do this if you have zero quarters? No, because the most you can have with five coins if none of them are quarters is 50 cents, but we need 80 cents.
Is it possible to do this if you have one quarter? No, because 80 minus 25 is 55, and the most you can have is 40 if the remaining four coins are dimes.
Is it possible to do this if you have three quarters? No, because 80 minus 75 is 5, and there is no way to make 5 cents with two coins.
So far we have proven that if 20 of the coins are pennies, then two of the other coins must be quarters. I sense we are tantalizingly close to a solution here.
I'll let you finish. Let me know what you come up with.
By the way, there are also solutions that have 15 or 10 pennies.
John
My calculator said it, I believe it, that settles it
Question 988346: To find a baseball pitcher's earned run average (ERA), you can use the formal Ei= 9r, in which E represents ERA, i represents the number of innings pitched, and r represents the number of earned runs allowed. Solve the equation for E. What is a pitcher's ERA if he allows 5 earned runs in 18 innings pitched?
Answer by macston(4006) (Show Source):
Question 988291: Simplify using order of operations
(9)(2)+3(155)8
Answer by EdenWolf(454) (Show Source):
Question 988328: g(h+2/3)=1 for h
Answer by solver91311(20879) (Show Source):
Question 988068: A=FVOV/T for OV (How do I solve it)?
Answer by Fombitz(25151) (Show Source):
Question 988034: A=FVOV/T for OV
Answer by stanbon(69061) (Show Source):
You can put this solution on YOUR website! A=FVOV/T for OV

Multiply thru by "T" to get:

AT = FVT  OV

OV = FVT  AT

OV = (FVA)T

Cheers,
Stan H.

Question 988036: A student was asked to use the formula for the perimeter of a rectangle, P=2L+2w, to solve for L. The student came up with an answer, P2w=2L. What error did the student make? Explain. Then solve for L.
Answer by josgarithmetic(13975) (Show Source):
Question 988041: A=FVOV/T for OV
Answer by josgarithmetic(13975) (Show Source):
Question 988035: C=Wtc/1000 for W
Answer by Alan3354(47455) (Show Source):
Question 987953: 2(x+y)+y
Answer by vleith(2950) (Show Source):
Question 987802: Solve the system of equations x+y=2 and x^2+2y^2=11
Answer by ikleyn(988) (Show Source):
Question 987464: Alexa and Zack are solving the following problem: The number of miles on Car A is 50 miles more than the number of miles on Car B, and the number of miles on Car B is 30 miles more than the number of miles on Car C. All the cars travel 50 miles in 1 hour. After 1 hour, twice the number of miles Car A is 70 miles less than 3 times the number of miles on Car C. How many miles were there on Car B initially? Alexa assumes there are m miles on Car B. Zack assumes there are m miles on Car C. Will Zack's answer be the same as Alexa's answer? Explain.
Answer by ankor@dixienet.com(18980) (Show Source):
You can put this solution on YOUR website! Alexa and Zack are solving the following problem:
The number of miles on Car A is 50 miles more than the number of miles on Car B,
a = b+50
and the number of miles on Car B is 30 miles more than the number of miles on Car C.
b = c+30
or
c = b30
All the cars travel 50 miles in 1 hour.
All travel at 50 mph
After 1 hour, twice the number of miles Car A is 70 miles less than 3 times the number of miles on Car C.
2(a+50) = 3(c+50)  70
2a + 100 = 3c + 150  70
2a = 3c + 150  70  100
2a = 3c  20
Replace a with (b+50), replace c with (b30)
2(b+50) = 3(b30)  20
2b + 100 = 3b  90  20
2b + 100 = 3b  110
2b = 3b  110  100
2b = 3b  210
210 = 3b  2b
b = 210 mi car B initially
then
a = 210 + 50
a = 260 car A initially
and
c = 210  30
c = 180 mi Car C initially
Alexa assumes there are m miles on Car B.\
Zack assumes there are m miles on Car C.
Will Zack's answer be the same as Alexa's No
Question 987501: x2y=1 solve for y
literal equations
Answer by Alan3354(47455) (Show Source):
You can put this solution on YOUR website! x2y=1 solve for y
===============
===================
Is there some reason you couldn't do that?
It's basic. Things are gonna get more difficult.
Question 987231: y=x+6;(5,11) tell weather the equation has the given ordered pair as a solution.
Answer by macston(4006) (Show Source):
Question 986894: Four numbers are such that the second number is 4 less than 3 times the first number and the third number is a quarter of the second number. The fourth number is five more than the first number. Determine the value of these four numbers if their sum is 115.
Answer by Timnewman(249) (Show Source):
You can put this solution on YOUR website! Hi dear,
Let the 1st number be a,
2nd =b
3rd=c
4th=d
From your question,
b=3a4(1)
c=b/4(2)
d=5+a(3)
From equ 1,
a=(b+4)/3(4)
Put 4 in 3,
d=5+(b+4)/3(5)
If the sum of a,b,c,d is 115,
Then,
Take the L.c.m and get
23b+92=1380
23b=138092
23b=1288
b=56
Put b=56 in equ 2,4,5, and get;
a=20,
c=14,
d=25
So the values of the fisrt,second,third,and fourth numbers are;20,56,14,and 25 respectively.
HOPE THIS HELPS?
Best wishes,
Timnewman::
Question 986858: What is the answer to 202(2 x 6)+8 divided by 4=
Answer by farohw(153) (Show Source):
Question 986292: Find the sum of a squared number and seven
Answer by Fombitz(25151) (Show Source):
Question 985971: Find two numbers that add to 3 and multiply to 40.
(Enter the two numbers separated by a semicolon.)
Thanks
Answer by ikleyn(988) (Show Source):
Question 986027: Find two numbers that add to 3 and multiply to 40.
(Enter the two numbers separated by a semicolon.)
Thanks.
Found 2 solutions by macston, Alan3354: Answer by macston(4006) (Show Source): Answer by Alan3354(47455) (Show Source):
Question 985922: y=x^210
9x^2y^2=90
The solution set is?
Found 2 solutions by MathLover1, ikleyn: Answer by MathLover1(11324) (Show Source): Answer by ikleyn(988) (Show Source):
You can put this solution on YOUR website! .
.
Substitute =  from the first equation into the second equation. You will get
 = .
Solve it:
 () = ,
 +  = ,
 + = .
It is a biquadratic equation. Don't be afraid ! Don't panic !
The Math gives you an opportunity to demonstrate your skills ! :)
Introduce new variable = .
Then you will get quadratic equation
 + = .
Its roots are (use the quadratic formula)
= 19, = 10.
Hence, = +/, +/.
Then from the first equation of the system
y =  = 19  10 = 9 OR y = 10  10 = 0.
Answer. The solutions are the pairs (x,y) = (, ), (, ), (, ) and (, ).
Question 985690: 4 culiques cost as much as 3 thingabobs
5 thingabobs cost as much as 6 whatsits.
What's the cost of 5 culiques and the cost of 4 whatsits?
Answer by macston(4006) (Show Source):
You can put this solution on YOUR website! .
4 culiques=3 thingabobs
1 culique=3/4 thingabob
.
6 whatsits=5 thingabobs
1 whatsit=5/6 thingabob
.
5 culiques=5(3/4 thingabob)=15/4 thingabobs
.
4 whatsits=4(5/6 thingabob)=20/6 thingabobs
Question 985453: Z z varies jointly as the square root of the product of x and y. if z = 3 when x = 3 and y = 12, find x when z = 6 and y = 64
Answer by josgarithmetic(13975) (Show Source):
Question 985451: Q varies jointly as r and s. If q= 2.4m when r =0.6 and s= 0.8, find q when r= 1.6 and s=.01.
Answer by stanbon(69061) (Show Source):
You can put this solution on YOUR website! Q varies jointly as r and s.
Q = k*r*s

Solve for "k" using "If q= 2.4m when r =0.6 and s= 0.8"
2.4 = k*0.6*0.8

2.4 = 0.48k
k = 2.4/0.48
k = 5

Find q when r= 1.6 and s=.01.
Q = 5*1.6*0.01
Q = 0.08
====================
Cheers,
Stan H.

Question 985328: what is the degree of x8=0?
Answer by Boreal(1464) (Show Source):
Question 985276: If y = 7 / (8 x + 1)
what is the yintercept of its graph?
Answer by josgarithmetic(13975) (Show Source):

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320
