Question

Use the substitution method to solve the following system of equations.
4x - y = 3
7x - 9y = -2

Answer 1

multiply the first by -9
-36x+9y=-27
7x-9y=-2
add em
-29x=-29
x=1
7(1)-9y=-2
-9y=-9
y=1
Answer's (1,1)

Answer 2

1,1 is right answer.

Answer 3

The first equation gives us\[4x-y=3\]\[y = 4x -3\]
Substitute into the second equation:
\[7x - 9(4x-3) = -2\]\[7x-36x+27=-2\]\[-29x=-29\]\[x=1\]\[y=1\] (the last step from equation 1)

Answer 4

Use the substitution method to solve the following system of equations.
x + y = 3
2x + 2y = 10 (2 points)Question 5 options:
1) (1, 2)
2) (2, 3)
3) No Solutions
4) Infinitely Many Solutions

Answer 5

No solutions:
\[2x + 2y =2(x+y) = 2(3) = 6\]
So the second equation is wrong.
(Step 3 done by substituting in equation 1)