Prove algebraically that the sum of the squares of two consecutive multiples of 5 is not a multiple of 10.

First let’s break this statement down. At the core of this sentence are two consecutive multiples of 5. How can we represent these using algebra? Let’s use 5a where “a” is an integer. A consecutive multiple of 5 would then be 5(a + 1). Use an example for “a” to understand this.Then, the SUM of the SQUARES refers precisely to the following:(5a)^2 + (5(a+1))^2which when expanded, becomes50a^2 + 10a + 25 Under evaluation, the first 2 terms will always be multiples of 10, but adding 25 stops the entire expression from being a multiple of 10.

DS
Answered by Daniel S. Maths tutor

5157 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Write 9sin(x) + 12 cos(x) in the form Rsin(x+y) and hence solve 9sin(x) + 12 cos(x) = 3


Find the x co-ordinates of the stationary points of the graph with equation y = cos(x)7e^(x). Give your answer in the form x = a +/- bn where a/b are numbers to be found, and n is the set of integers.


find the definite integral between limits 1 and 2 of (4x^3+1)/(x^4+x) with respect to x


What is the sum of the infinite geometric series 1 + 1/3 + 1/9 +1/27 ...?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning