Solve the simultaneous equations: 3x+2y=4 and 4x+5y=17

To solve this equation we need to make it so the x's or the y's of each equation are equal. To do this we need to multiply one or both equations so we can take or add one of the equations to the other. We are going to equate the y's for this example, to do this we need to find the lowest common multiple of 5 and 2 which is 10. This means we want both the y values to have a 10 in front of them, which means we have to times equation 1(3x+2y=4) by 5 and equation 2(4x+5y=17) by 2. This gives us the new equations of 15x+10y=20(1) and 8x+10y=34(2). We can now take equation 1 away from equation 2 which gives us 7x=-14 which shows x to be -2. We can then plug this x value into either of the original equations to find our y value. If we plug it into the original equation 1 we get 3(-2)+2y=4 which can rearranged to show that 2y=10 and therefore y=5. This gives us the final answer of x=-2 and y=5

AH
Answered by Arron H. Maths tutor

17069 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A ball, dropped vertically, falls d metres in t seconds. d is directly proportional to the square of t. The ball drops 45 metres in the first 3 seconds. How far does the ball drop in the next 7 seconds?


How do I know whether to use sin, cos, or tan in trigonometry?


Solve simultaneously, x+y=2 and 4y^2-x^2=11


Express 56 as the product of its prime factors


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