Question

questions: 12

1. which expression can be substituted for y in the top equation of the following system to solve the system by substitution? what is the solution?

-2x + 5y = -14
3x + y = 4
$\frac{4}{3}$x, (-3,13)
3x - 4, ($\frac{6}{13}$,$\frac{34}{13}$)
-3x + 4, (-2,2)
-3x + 4, (2, -2)

Explanation:

Step1: Isolate y in bottom equation

$3x + y = 4$
$y = -3x + 4$

Step2: Substitute y into top equation

$-2x + 5(-3x + 4) = -14$
$-2x -15x +20 = -14$
$-17x = -34$
$x = 2$

Step3: Find y with x=2

$y = -3(2) + 4$
$y = -6 + 4 = -2$

Answer:

D. $-3x + 4, (2, -2)$