Question

please do question 7 please

Answer 1

Answer:

208

Step-by-step explanation:

7.

Given Equation is 3x - (4/x) = 4

On Squaring both sides, we get

⇒ (3x - 4/x)² = 4²

⇒ 9x² + (16/x²) - 2(3x)(4/x) = 16

⇒ 9x² + (16/x²) - 24 = 16

⇒ 9x² + (16/x²) = 40

Now,

Given: 27x³ - (64/x³)

= (3x)³ - (4/x)³

∴ a³ - b³ = (a - b)(a² + ab + b²)

= (3x - 4/x)(3x² + 16/x² + (3x)(4/x))

= 4(40 + 12)

= 4(52)

= 208

Hope it helps!