Maths Olympiad Prep

Track / Stage 5 / 89 of 400 #689 of 1964

Problem 689

AIME late
Algebra Difficulty 5.2 Find the answer

Suppose that

M=15+24×3342÷51N=1524×33+42÷51 \begin{aligned} M & =1^{5}+2^{4} \times 3^{3}-4^{2} \div 5^{1} \\ N & =1^{5}-2^{4} \times 3^{3}+4^{2} \div 5^{1} \end{aligned}

What is the value of M+NM+N ?

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Official solution

Since M=15+(24×33)(42÷51)M=1^{5}+\left(2^{4} \times 3^{3}\right)-\left(4^{2} \div 5^{1}\right) and N=15(24×33)+(42÷51)N=1^{5}-\left(2^{4} \times 3^{3}\right)+\left(4^{2} \div 5^{1}\right), then when MM and NN are added the terms (24×33)\left(2^{4} \times 3^{3}\right) and (42÷51)\left(4^{2} \div 5^{1}\right) "cancel" out.

Thus, M+N=15+15=2M+N=1^{5}+1^{5}=2.

ANSWER: 2

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.