Answer:
a = - 8
Explanation:
A polynomial divided by factor (x - h) has a remainder given by f(h)
Here the divisor is (x - 2), thus f(2) gives the remainder, that is
2³ + 2(2)² - 7(2) + a = 4 ← 4 being the remainder
8 + 8 - 14 + a = 4, that is
12 + a = 4 ( subtract 12 from both sides )
a = - 8