Question

If 5 Δ
6 = 1331, 6 Δ
1 = 343, and 2 Δ
x = 729, then determine the value of x.
5
6
7
8

Answer 1

Answer:

7

Step-by-step explanation:

(5+6)^3 = 1331

(6+1)^3 = 343

(2+x) ^3 = 729

2^3 + x^3 + 3(2)^2 (x) + 3(x)^2 (2) = 729

8 + x^3 + 12x + 6x^2 = 729

x^3+ 6x^2+ 12x + 8 = 729

when x = 7,

7^3 + 6(7)^2 + 12(7) + 8

343 + 6(49) + 84 + 8

343 + 294 + 84 + 8

637 + 92

729