Question

Solve the following system using substitution. Write the solution as an ordered pair, (a, b).

b = a – 4
2a – 3b = -2

Answer 1

okay just equation 1 has b= a - 4 we can plug in a- 4 for b in equation 2 to give you;

2a - 3(a - 4) = -2

2a - 3a +4= -2

-a + 4 = -2

-a = -6

divide by negative 1 to make a postive
a= 6 now you can plug in 6 into either equation to solve for b

but i would use equation 1 since its so short b = 6- 4 , b= 2

(6, 2)

Answer 2

i hope that helps if your confuse about anything with the above solution just ask and ill try to clarify

Answer 3

The only problem is, a=6 b=2 does not satisfy the original equations.

If you work it more carefully, you will wind up with

a=14
b=10

hint: -3(a-4) is not -3a+4