RRB Group-D Model Paper 14 with answers for online practice

Question : 44 of 100

Marks: +1, -0

f a + b = 11 and ab = 30, then find the value of

(a^3 + b^3)

Solution:

Tips & Tricks
Given:
a + b = 11 and ab = 30
Formula:

a^3 + b^3 = (a + b)^3 – 3ab(a + b)

Calculation:

a^3 + b^3 = (a + b)^3 – 3ab(a + b)

⇒

a^3 + b^3

= 113 – 3 × 30 × 11
⇒

a^3 + b^3

= 1331– 990
⇒

a^3 + b^3

= 341

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