Solve algebraically: 6a+3b=24, 3a-b=7

Equation 1 : 6a+3b=24Equation 2: 3a-b=7
Rearrange equation 2 to make b the subject:add b to both sides : 3a=7+bminus 7 from both sides: 3a-7=b
Substitute this into Equation 1 : 6a + 3(3a-7)=24
Multiply out the bracket: 6a + 9a - 21 = 24
Simplify:add the a terms together: 15a - 21=24add 21 to both sides: 15a=45divide by 15: a=3
Sub into Equation 2:3(3)-b=7multiply out bracket: 9-b=7add b to both sides: 9=7+bminus 7 from both sides: 2=b
Answer: a=3 b=2

Answered by Emily G. Maths tutor

4744 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations 3x + y = –4 and 3x – 4y = 6


2x + 4 = 4y ; 3y + 3 = 3x. What is x and y respectively?


A sequence increases by 5 each time and the first term is x. The sum of the first four terms is 54. Set up and solve an equation to work out the value of x.


How do you solve inequalities when they involve quadratics? i.e x^2+x-6<0


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences