Systems by substitution

The question

y = 4x − 1−6x − y = 1

y = 4x − 1 −6x − y = 1

How it works.

y = 4x − 1

−6x − y = 1

−6x − (4x − 1) = 1

x=0

y=−1

x = 0andy = −1

01
Two equations, two letters. First get down to one equation with one letter.
02
The first equation already says what y is. So wherever the second equation has a y, that whole expression can go in its place — which leaves only x.
03
Now multiply out, collect the x terms and solve. That gives x = 0.
04
Now put x back into the first equation to find y: y = 4(0) − 1 = −1.
05
Check the pair in the other equation. The solution is (0, −1).