Question

the value of a^3+b^3, if a+b=6 and ab=3 is- (a)270 (b)162 (c)216 (d) none of these​

Answer 1

ANSWER :–

a³ + b³ = 162

EXPLANATION :–

GIVEN :–

• a + b = 6

• ab = 3

TO FIND :–

a³ + b³

SOLUTION :–

• We know that –

☞ (a + b)³ = a³ + b³ + 3ab(a + b)

• Now put the values –

=> (6)³ = a³ + b³ + 3(3)(6)

=> 216 = a³ + b³ + 9 × 6

=> 216 = (a³ + b³) + 54

=> a³ + b³ = 216 - 54

=> a³ + b³ = 162

☞ Therefore, option (b) is correct.

EXTRA INFORMATION :–

(1) (a - b)³ = a³ - b³ - 3ab(a - b)

(2) (a + b)² = a² + b² + 2ab

(3) (a - b)² = a² + b² - 2ab

(4) (a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca

Answer 2

ak has explained............. ...............

thank u