Solve the system, using substitution.

3a - b = 11 and 2a + 3b = 0

Question

Solve the system, using substitution.

3a - b = 11 and 2a + 3b = 0

anonymous · Answer

I am guessing 3,-2?

anonymous · Answer

You have to cancel on of the variables first:

3a - b = 11 (multiply by 2 on both sides)

2a +3b = 0 (multiply by 3 on both sides)

This makes both of the equations both have 6a. Then you cancel "a" out:

  6a-2b = 22
-(6a-9b =  0)
____________
0a-7b=22
-7b=22
b= -22/7

Subsitute b in for -22/7 in one of the equations, and solve for a.

Always check you work!

anonymous · Answer

That isn't a answer in the multiple choice.

anonymous · Answer

I made an error:

  6a-2b = 22
-(6a-9b =  0)
____________
0a+7b=22
7b=22
b= 22/7

Is that right?