Solve the Simultaneous Equation: 2x + 3y = 15 and 5x + 4y = 13

Primarily, we should attempt to make either the x or y values of either equation be the same value, or the equivalent negative value. This is so we can add or subtract the equations to leave us with one variable. In this case, we should multiply the first equation by 5 to leave us with 10x + 15y = 75, and multiply the second by 2, leaving us with 10x + 8y = 26.Then we should subtract the second equation from the first equation, leaving us with 7y = 49. By dividing both sides by 7, we find our first variable y. Y is therefore equal to 7.
Then if we look at the original question, y can be inserted into either of the equations. If we take the first one, the equation that results is 2x + (3*7) = 15. The three and the seven multiply so 2x + 21 =15. If we subtract 21 from both sides, the equation we are left with is 2x = -6. By dividing both sides by 2, the answer for variable x is -3.Thus the solution to the simultaneous equation is x = -3 and y = 7

Answered by Luke H. Maths tutor

7411 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

2x + y = 1, x^2 + y^2 = 1


Make x the subject of the formula y=(4x+5)/x


Solve the simultaneous equations x^2+y^2=1 and x+2y=1


Frank buys a car at the start of 2015, for £12,000. Each year the value fo the car depreciates by 9%. What was the value of the car at the end of 2019?


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