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.

Answered by Daniel S. Maths tutor

4302 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find dy/dx for y=x^2 * sin(x)


Express 2Cos(a) - Sin(a) in the form RCos(a+b) Give the exact value of R and the value of b in degrees to 2 d.p.


A curve (C) with equation y=3x^(0.5)-x^(1.5) cuts the X axis at point A and the origin, calculate the co-ordinates of point A.


The equation of a line is y=e(^2x)-9 and the line has points at (0,a) and (b,0). Find the values of a and b.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences