Question

If a+2b=5 prove that a^3+8b^3+30ab=125

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Solution:

Given a+2b = 5 ----(1)

To prove:

a³+8b³+30ab=125

Explanation:

On cubeing equation (1) , we get

(a+2b)³ = 5³

=> a³+(2b)³+3×a×2b×(a+2b)=125

/we know the algebraic identity:

$\boxed{(x+y)^{3} = x^{3}+y^{3}+3xy(x+y)}$

=> a³+8y³+6ab×5 = 125

/* From equation (1) , we get */

=> a³+8y³+30ab = 125

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