Question

X
(2x - 7)^3= (2x)^3- 7^3
= 8x3 - 343

Answer 1

(2x - 7)³ ≠ (2x)³- 7³

Explanation:

(2x - 7)³= (2x)³- 7³

Use pascal's triangle to expand left side. Simplify all else.

(2x)³ + 3(2x)²(-7)¹ + 3(2x)¹(-7)² + (-7)³ = 8x³- 343

8x³ + 3(4x²)(-7) + 3(2x)(49) + (-7)³ = 8x³- 343

8x³ - 84x² + 294x - 343 = 8x³- 343

LS ≠ RS