Answer:
a=1/2
Explanation:
From the question, the expression a(8x+7) is equivalent to 4x+3.5
Which means that multiplying 8x by a gives 4x and multiplying 7 by a gives 3.5
So, we can write the following to find the value of a

we can write the following
8ax=4x

Hence the value of a is 1/2