# If a + B = 8 and Ab = 6, Find the Value of A3 + B3 - Mathematics

If a + b = 8 and ab = 6, find the value of a3 + b3

#### Solution

In the given problem, we have to find the value of  a^3 +b^3

Given  a+b = 8.ab = 6

We shall use the identity  a^3 + b^3 = (a+b)^3 ab(a+b)

a^3 + b^3 = (a+b)^3- 3ab (a+b)

a^3 +b^3 = a(8)^3 - 3 3 xx 6 (8)

a^3 +b^3 = 512 - 144

a^3+b^3 = 368

Hence the value of ia^3 +b^3 is 368 .

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#### APPEARS IN

RD Sharma Mathematics for Class 9
Chapter 4 Algebraic Identities
Exercise 4.4 | Q 4 | Page 25