Solve the following simultaenous equations

6a + 3b = 7 (1) 4a + 4b = 12 (2) We need to eliminate one of the variables in our simultaneous equations in order to be able to find a numerical value. As the same signs are used in both equations (i.e. addition), this could be achieved by subtracting one equation from the other, once one of the variables are equated (thus removing this variable). For example: (1) x 4 gives 24a + 12b = 28 (2) x 3 gives 12a + 12b = 36 Thus the b variable is equal in both equations and if we now subtract (2) from (1) we have an equation in a: 12a = -8 and solving gives a = -2/3. Substitute a back into our original (1): (6 x -2/3) + 3b = 7 3b - 4 = 7 b = 11/3 Check in original (2): (4 x -2/3) + (4 x 11/3) = -8/3 + 44/3 = 12 (as this is equal to (2) the values for a and b are correct)

MJ
Answered by Millie J. Maths tutor

3302 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve x^2-5x+6=0


Determine the next two terms in this sequence: 2, 7, 9, 16, 25, ... , ...


Solve the simultaneous equations: 5x+5y = 6 7x+3y = 6


Sophie had 3 piles of coins, A, B and C. Altogether there was £72. Pile B had twice as much as pile A. Pile C had three times as much as pile B. How much money was in Pile C?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences