Question 134802
You would solve this problem using substitution.  The steps for substitution are:<br>

1) Solve one of the equation for an isolated variable.
2) Plug in step 1 into the remaining equation and solve for the one variable.
3) Plug in step 2 into step one and find what the isolated variable is.
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3b - a = -7
5a + 6b = 14<br>

Since 3b - a = -7 has a variable alone we will solve this equation for a.<br>

3b - a = -7
-a = -7 - 3b
a = 7 + 3b<br>

now plug that into 5a + 6b = 14 and solve for b.<br>

5a + 6b = 14 --> Plug in a = 7 + 3b into the second equation
5(7 + 3b) + 3b = 14 --> Distribute the 5 though
35 + 15b + 3b = 14 --> Combine like terms
35 + 18b = 14 --> Subtract 35 from both sides
18b = -21 --> Divide both sides by 18
b = -7/6<br>

Now we plug b = -7/6 into a = 7 + 3b and solve for a.<br>

a = 7 + 3b
a = 7 + 3(-7/6)
a = 7 - 7/2
a = 7/2<br>

so your solution is a = 7/2 and b = -7/6.