Question

If 3x = y-5 and x = -4, then y=

Answer 1

3( -4 ) = y - 5
-12 = y - 5
y = -7

Answer 2

$3x=y-5\ \ \ \ |+5\\3x+5=y\to y=3x+5\\\\\text{substitute the value of x to the expression}\\\\y=3(-4)+5=-12+5=-7$

Answer: y = -7.