Question

There is a value of a such that subtracting a-4 from 4a+16 gives an answer of -25. What is that value of a? (We suggest that you check your answer)

Any help is to be valued highly and much appreciated! Thank you!

Answer 1

`\bf (4a+16)-(a-4)=-25\implies 4a+16-a+4=-25 \\\\\\ 3a=-25-16-4\implies 3a=-45\implies a=\cfrac{-45}{3}\implies \boxed{a=-15}`