What is the solution of the system ??

4x+3y= 12
7x+5y=26
a.(18,20)
b.(18,-20)
c.(-20,18)
d.(20,18)
is it c?

to eliminate y, multiply the first equation by 5 and the second equation by 3:

20 x + 15 y = 60
21 x + 15 y = 78
--------------------subtract
-1 x = - 18
so
x = 18
so
4(18) + 3 y = 12
72 + 3 y = 12
3 y = -60
y = -20
-----------------------
check that to be sure
7(18) + 5 (-20) = ???? 26
126 - 100 = 26 sure enough it checks

so its b @damon?

nope. you helped alot.

@damon can you help me with this one ?

What is the solution of the system? use substitution . 4x+2y=10, y=-3x+6

My answer chosies are
a. (1,-3)
b.(1,3)
c.(3/10, 4/5)
d.(-2,-2)

is it b? @damon

Henry and I have both done this already, scroll down.

yall have helped alot .

To solve the system of equations, you can use the method of elimination or substitution. Let's use the method of elimination:

1. Multiply the first equation by 7 and the second equation by 4 to make the coefficients of x in both equations equal:
Equation 1: 7(4x + 3y) = 7(12) -> 28x + 21y = 84
Equation 2: 4(7x + 5y) = 4(26) -> 28x + 20y = 104

2. Now subtract the first equation from the second equation:
(28x + 20y) - (28x + 21y) = 104 - 84
This simplifies to: -y = 20

3. Solve for y by dividing both sides of the equation by -1:
y = -20

4. Substitute the value of y back into one of the original equations, let's use the first equation:
4x + 3(-20) = 12
Simplify:
4x - 60 = 12
Add 60 to both sides:
4x = 72
Divide both sides by 4:
x = 18

So, the solution to the system of equations is x = 18 and y = -20. The correct answer choice is (b) (18, -20).

Yes, but no need to ask is there?

http://www.jiskha.com/display.cgi?id=1452020437

Start trying to do them and stop asking us to do it all.