Solve algebraically the simultaneous equations 2x+y=5 and 3x+y=7, for x and y.

Assign 2x+y=5 to be 'Equation 1,' and 3x+y=7 to be 'Equation 2.'The steps to solving for x and y are: 1.get rid of one variable (being either x or y) 2.solve for the other variable 3.substitute the now known value of that variable into the equation to solve for the other variable.For this question: 1.To get rid of one variable, we want the coefficient of it to be the same so that it will cancel out when the equations are either added or subtracted together. Notice in this question, in both equations, y has the coefficient of 1. To get rid of it, we want to subtract one equation from the other as 'y-y=0.' 2.We now subtract 'Equation 1' from 'Equation 2.' This gives us an equation of x=2. We do not need to do anything more to this as we have now solved for x. 3.We substitute x=2 back into either 'Equation 1' or 'Equation 2' to solve for y.Choosing 'Equation 1' gives:2(2)+y=54+y=5y=1We have solved the simultaneous equations and obtained values of x=2 and y=1. We can check these values by substituting them back into the equations. Eg. (using 'Equation 2') 3(2)+1=7; 7=7 so it is correct.

NK
Answered by Natalie K. Maths tutor

4790 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Consider an isosceles triangle ABC, where AB=AC=1, M is the midpoint of BC, and <BAM=<CAM=x. Use trigonometry to find an expression for BM and by finding BC^2, show that cos2x = 1 - 2(sinx)^2.


Steve wants to put a hedge along one side of his garden. He needs to buy 27 plants for the hedge. Each plant costs £5.54 Steve has £150 to spend on plants for the hedge. Does Steve have enough money to buy all the plants he needs?


Factorise 3x^3y^2-6x^2y+9xy


Derive X^2 + 2x


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