W = L - 7
WL = 78
(L-7)L = 78
L^2 - 7L - 78 = 0
Factorize: (L-13)(L+6) = 0
L = 13 or -6
A length cannot be negative, so the length must be 13 miles.
The width is 13-7 = 6 miles.
The answer is Difference of Cubes.
Difference of cubes is a³ - b³.
27 can be written as 3³ (= 3 × 3 × 3 = 27). So, a = 3.
8 can be written as 2³ (= 2 × 2 × 2 = 8). So, b = 2.
Difference of cubes can be expressed as:
a³ - b³ = (a - b)(a² + ab + b²)
⇒ 3³ - 2³ = (3 - 2)(3² + 3×2 + 2²) = 1 × (9 + 6 + 4) = 1 × 19 = 19
⇒ 27 - 8 = 19
Answer: A, because it is a 30, 60, 90 triangle. To get the 34 they had to times the number by 2 so you divide that by 2 and it gives you 17 then you have the square root of 3* 17, that doesn’t mathematically work so it stays as 17*the square root of 3
Do what the problum ids telling you than apply it to the math and you will always get the right answer