How do you solve the system $y = 5x - 7$ and $-4 + y = -1$ by substitution?

Question

1262 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-05-21T08:16:45

$y = 5x - 7$ ..........equation $(1)$

$-4 + y =-1$ ......equation $(2)$

substituting equation $(1)$ in equation $(2)$

$-4 + y =-1$
$-4 + (5x -7)= -1$
$5x -11= -1$
$5x = 10$
$x = 2$

substituting the value of $x$ in equation $(1)$
$y = 5x - 7 = 5.(2) -7$
$y = 10 -7 = 3$

The solutions for the system of equations are :
$color(blue)x=2$
$color(blue)y=3$

How do you solve the system y = 5x - 7y = 5x - 7 and -4 + y = -1 -4 + y = -1 by substitution?