Question

IF 2a=3+2b prove that 8x3+8b2-36ab

Answer 1

Answer: 27

Given: 2a = 3 + 2b

To find: Value of 8a³ + 8b² - 36ab

2a = 3 + 2b

Cubing both sides:

(2a)³ = (3 + 2b)³

=> 8a³ = (3)³ + (2b)³ + 3 × 3 × 2b (3 + 2b)

=> 8a³ = 27 + 8b³ + 18b × 2a

=> 8a³ = 27 + 8b³ + 36ab

=> 8a³ - 8b³- 36ab = 27

Thus, value of 8a³ + 8b² - 36ab is 27.

Answer 2

$\huge{\underline{\underline{\huge{\bold{AnsweR \: :-}}}}}$

$\large\sf\color{blue}{Given:}$ 2a = 3 + 2b

$\large\sf\color{blue}{To\: Find}$ Value of 8a³ + 8b² - 36ab

2a = 3 + 2b

$\large\sf\color{blue}{Cubing\:Both\:Sides:}$

(2a)³ = (3 + 2b)³

=> 8a³ = (3)³ + (2b)³ + 3 × 3 × 2b (3 + 2b)

=> 8a³ = 27 + 8b³ + 18b x 2a

=> 8a³ = 27 + 8b³ + 36ab

=> 8a³- 8b³- 36ab = 27

$\large\sf\color{red}{Thus, \:value\: of\: 8a³ \:+ 8b² - 36ab\: is \:27}$