Answer:
(a) 
(b) 
Step-by-step explanation:
Given

Solving (a): Simplify

Open brackets

Collect Like Terms

Simplify Like Terms

Solving (b): Simplify when a = 2 and b = -1





Hence:

Answer: 0
Step-by-step explanation:
first you distribute the negative which gives you 7-3-4 which equals 0
6x + 18, that is the answer
From what I can see, you are on the right track.
one thing you could have done is combine like terms.

Now just take the square root of 7 squared. That takes out the squared making your answer 7 or G.
You were on the right track, you just skipped a step.
hope this helped!