Answer:
For the first case:
a = 4 x^2
For the second case:
a = 4 x^2 + 27 x + 45
Step-by-step explanation:
The area of a rectangle is:
a = L * w
w = x
L = 4 x
a = 4x * x
a = 4 x^2
If each dimension is increased by 3, we got:
w = x + 3
L = 4 * (x + 3) + 3
a = (4 * (x + 3) + 3) * (x + 3)
a = (4x + 12 + 3) * (x + 3)
a = (4x + 15) * (x + 3)
a = 4 x^2 + 12x + 15x + 45
a = 4 x^2 + 27x + 45
