Solve the simultaneous equations 3x + y = –4 and 3x – 4y = 6
Rearrange first equation so we can eliminate one variable: y= - 4 -3x We can then plug this into the second equation so we get rid of the y's and just have x's: 3x-4(-3x-4)=6Simplify this: 3x + 12x+16=6 which gives 15x = -10 and then x=-10/15 = -2/3Can plug x back in to any equation to find out y, this gives: y = - 4 -3(-2/3)y= - 4 +2 so y= -2Final answer: x= -2/3 and y= -2
AC
Related Maths GCSE answers
All answers ▸Solve these simultaneous equations. 2x + y = 10 and 3x + 4y = 25.
Solve 5 < x² + 1 < 10
A bag has 24 sweet of different colours: 10 red, 8 blue and 6 yellow. What is the probabilty of not getting a blue sweet ?
The perimeter of an isosceles triangle is 16cm the lengths of the sides are (x+3)(this is the length of the opposite side as well) and (x+4). Determine the value of x .