Question

12 cube x + 18 cube x ends in

Answer 1

12 cube x +18 cube x = 7560

Answer 2

$12^{3} x + 18^{3} x \\= ( 12^{3} + 18^{3})x \\= (12+18)[ 12^{2} - 12 \times 18 + 18^{2} ] x$

$\underline { \blue { By \: Algebraic\: Identity }}$

$\boxed { \pink { a^{3} + b^{3} = (a+b)(a^{2}-ab+b^{2})}}$

$= 30( 144 - 216 + 324 )x \\= 30(468-216)x \\= 30 \times 252x \\= 7560x$

Therefore.,

$\red{12^{3} x + 18^{3} x\: ends \: in } \green { 0 }$

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