Given the two equations [1](3x + 4y = 23) and [2](2x + 3y = 16), find the values of x and y

One way to find the values of x and y is to substitute the value of x into one of the equations. To sub in x we need to rearrange an equation to get x on its own. We can change the second equation to x = (16 - 3y)/2. We then sub this into equation 1 and get3[(16 - 3y)/2] + 4y = 23. Expanding this out gets 24 - (9/2)y + 4y = 23. -(9/2)y + 4y = -1 -1/2y = - 1 -y = -2 y = 2. This can then be substituted back into an equaiton to get x. Subbing back into equation 1 gets 3x + 8 = 23. 3x = 15 x = 5This can then be verified by subbing in our values back into equation 2 to check that our answers are correct.

SH

Related Maths GCSE answers

All answers ▸

Factorise fully X^2 - 6X + 8


y is directly proportional to (x-1)^2. When x=5, y=4. Find y when x=7.


Solve these equations simultaneously: (1) 5x - 10z = -45 and (2) 9x = -5z + 80


What is the gradient of the line passing through the point (1,2) and (5,5)? What is the equation of this line? What is the equation of the line perpendicular to this line that passes through the origin (0,0)?