Solve these simultaneous equations: 3x-5=-4y and 2xy=-4

First start with 2xy=-4, rearrange to find in terms of x, x=-2/y. Substitute this into the other equation (3x-5=-4y), producing -6/y -5 =-4y.Times every term by -y resulting in 6+5y=4y2 .Rearrange to 4y2-5y-6=0 and solve the quadratic (4y+3)(y-2) = 0 resulting in y=2 or y=-3/4.Substitute into the original equation (2xy=-4) and rearrange for x. x=-2/y. Producing x=-1 or x=8/3

Answered by Amelia S. Maths tutor

2636 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations, 3x + 2y = 4 (1) 4x + 5y = 17 (2)


Solve the simultaneous equation: 2x + 3y = 6, 3x + 2y = 5.


Express 280 as a product of its prime factors.


Adam can pay for his gym membership in one go at £180 or in monthly sums of £20. Work out the percentage increase of paying monthly to 1 decimal place.


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