Question

If y=-x+1 and y=3x+1, what is the numerical value of (3x+y)

Answer 1

Add the 2 equations together

y = -x+1

y  =3x+1

========

2y = 2x+2

divide by 2

y = x+1

y = x+1

y = -x+1

=======    add these two equations together

2y = 2      divide by 2

y = 1

y = x+1

1 = x+1

x=0

3x+y=3(0) +1=1

Answer =1