Solve 7(x+2)=5x+21

The first thing we must realise is that there are brackets in this equation and thus this has to be dealt with. We expand out the brackets on the left side by multiplying 7 by x and 2 to obtain '7x+14'. We now have the equation '7x+14 = 5x +21'. We have to collect the x terms on one side, preferably the left hand side, and the other constants on the other side. Subtracting 5x from both sides, we get '2x+14 = 21'. We repeat the same by subtracting 14 from both sides to get '2x = 7'. To find the solution to this equation we have to find out the value of x and thus if we divide both sides by 2 we get the final solution, x=3.5 or 7/2

Answered by Maths tutor

3502 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A metal Sphere of radius Ym is melted down and remade into a cylinder of the same volume with height Ym with circular ends of radius 3m, find Y


Solve for x : 2x-15=-2x-7


A bottle contains 300ml of medicine, the dose for a child can be given by (m*a)/150 where m is the child's age in months and a is the adult dosage of 40ml. If you need 2 doses a day, how long will the medicine last until it's empty for a 2y/o child?


What is solution by substitution?


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:

© 2026 by IXL Learning