l = 2w + 4
l * w = 48
We can substitute l with its value:
2w + 4 * w = 48
2w^2 + 4w - 48 = 0
2(w^2 + 2w - 24) = 0
2(w+6)(w-4) = 0
w = {4, -6}
You can look for the number 16 on the x-axis. (bottom line) and put a finger there. Then, look for 19 on the y -axis (left line) and put a finger there. Trace your left finger to the right and your right hand up until they meet. That is (16,19)
(48a^3 + 32a^2 + 16a) / 4a = ?
48a^3 / 4a = 12a^2
32a^2 / 4a = 8a
16a / 4a = 4
so
(48a^3 + 32a^2 + 16a) / 4a = 12a^2 + 8a + 4
Answer is D. 12a^2 + 8a + 4
