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

AS

Related Maths GCSE answers

All answers ▸

Solve the quadratic equation X^2+3X+2=0 by factorisation.


There are 10 boys and 20 girls in a class. In a class test, the mean score of the boys is 77. The mean score of the girls is 80. What is the mean score of the whole class?


What is BODMAS?


Expand the brackets (2x + 3)(3x - 1)