Question

Solving systems of equations by substitution Y=6x y=5x+7

Answer 1

Y=6x (1)
y=5x-7 (2)

Substitute y into (2)
(6x)=5x-7 -- subtract 5x from both sides
x=-7

Sub x into 1
y=6(-7)
y=-42

x=-7
y=-42

Answer 2

First substitute 'y' in 2nd equation by right side of 1st one and you get:
$Y=6x$
$6x=5x+7$
now substract 5x from both sides of 2nd equal and you get:
$6x-5x=5x+7-5x$
as a result of the equal above you get:
$x=7$
now substitute x in very first equation by the result from above (x=7):
$Y=6*7=42$
$x=7$