Practice30 Create account

Two numbers add up to 9 and the sum of their squares is 41. What is the sum of their cubes?

Competition practiceAlgebra

A189
B729
C369
D209

Step-by-Step Solution

x y = (81 - 41) /2 = 20, so x^{3} + y^{3} = (x + y)^{3} - 3 x y (x + y) = 729 - 540 = 189. (5^{3} + 4^{3} .)

Answer: A) 189

Master this topic in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All Algebra practice questions

More Algebra practice

For a = 2026, b = 2025 and c = 2024, find a³ + b³ + c³ − 3abc.Non-zero numbers a and b satisfy a/b + b/a = 1. What is a³ + b³?The numbers a, b, c satisfy a + b + c = 10 and ab + bc + ca = 31. Find a³ + b³ + c³ −…The denominator of a fraction is 4 more than its numerator. When 3 is added to both, the…A two-digit number equals 4 times the sum of its digits, and its units digit is 3 more…