Answer:
y = 247
Step-by-step explanation:
The given cubic model that expresses the value of y is
y = 5a³ - 2a² + a - 45
We have to find the value of y at a = 4
We can calculate the value of y by putting a = 4
y = 5(4)³ - 2(4)² + 4 - 45
= 5(64) - 2(16) - 41
= 320 - 32 - 41
= 247
y = 247