I am having some (major) problems trying to rearrange an equation which defines a line on a graph- which Excel produced. They are in the format y=(-ax^2)+bx. I am trying to rearrange the equation to give x=.....
The two equations are as follows.
y= -0.4615x^2+29.381x in other words y = (-0.4615*x^2) + (29.381*x)
y= -0.7565x^2+41.689x in other words y= (-0.7565*x^2) + (41.689*x)
Unfortunately, my ability does not extend beyond putting the brackets in, and despite numerous attempts, I cannot work out how to calculate x.
If anyone is able to help, it would be fantastic!
Thanks for the reply. However, I can't seem to get it to work.
If y=-0.4615*(x^2)+29.381*x, and x=20, then y=403.02.
However, using the equation you gave, if you use 403 as the y value, then I cannot get 20 as the value for x.
Am I just being stupid here or what!?