Answer:
a is 39
b is 57
Explanation:
you were given two different expressions to substitute.
the first one is p = 8 and d = 1/7
so we substitute into 5p - 7d
that is 5(8) - 7(1/7)
we get 40 - 1
which if we go ahead to evaluate we get 39
The second one p = 3 and d = -6
so we get 5(3) - 7(-6)
we get 15 - (-42)
if we go ahead to evaluate we get 15 + 42
two negative meeting each other gives you positive.
then it going too be 57