Question

to prove that 125+x³=(5+X)³-15x(5+X)
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Answer 1

Step-by-step explanation:

LHS,

125+x³

= 5³+x³

so now applying,,

(a+b)³ = a³+b³+3ab(a+b)

so, (5+x)³ = 5³+x³+15x(5+x)

so,, 125+x³ = (5+x)³-15x(5+x)

hence proved.......