Question

What is the resulting equation when the expression for y in the second equation is substituted into the first equation?

3x + y = 1
y = 6 - 4x
-x + 6 = 1
x + 6 = 1
7x + 6 = 1

Answer 1

take the second equation already set to y and substitute it into the first equation for y...

3x + (6 - 4x) = 1  ... now we simplify
3x + 6 - 4x = 1  .....now combine like terms
-x + 6 = 1    .....

Answer 2

y=6-4x
sub 6-4x for y

3x+y=1
3x+(6-4x)=1
3x+6-4x=1
3x-4x+6=1
-x+6=1

3rd option