Solve the simultaneous equations: 5x + y = 21 and x - 3y = 9
label equation 5x + y = 21 as (1) and equation x - 3y = 9 as (2) multiply equation (2) by 5 to get : 5x - 15y = 9 (3) then subtract equation (1) from equation (2) in order the eliminate the x variable -16y =24 solve for y: y = -3/2 then substitute the value for y =-3/2 into the first equation and solve for x to determine: x=9/2
SG
Related Maths GCSE answers
All answers ▸A right angled triangle has two smaller sides length 3 and 4, what is the length of its longest side?
What is the slope of the function y=3x(squared)-9x+7 at x=2.
How do I simplify fully (p^3 x p^4)/p^2?
Solve the simultaneous equations; 5x + 2y = 11, 4x – 3y = 18