Answer:
169/4
Step-by-step explanation:
x² - 13x + c
x² -2(x)(13/2) +(13/2)²
(13/2)² = 169/4 or 42 ¼
A = L * W
A = 7 * 4
A = 28 sq ft....this is the area of her garden
and if each plant uses 1 sq ft, then there will be (30 - 28) = 2 plants leftover
So the answer is choice D. You can check this by differentiating the right hand side and you'll get x^3 back again.
This answer can be found by using the power rule for integrals. That rule is