F(x) = 2x^2 + 5x
f(3b) = 2(3b)^2 + 5(3b) = 2(9b^2) + 15b = 18b^2 + 15b
Isolate the x and the 2 from the top of the equation, then cancel those out from the bottom, then divide out the -1. after that you are left with -6x²+2x-4
The slope would be -1 because of the x
We have 10 ml of 20% acid to which we need to add "x" milliliters of 100% acid to make 50% acid.
.20 * 10 + 1.00x = .50 * (10 +x)
in which "x" is the volume of the 100% acid to be added.
2 + x = 5 + .5 x
.5x = 3
x = 6 milliliters
Source:
http://www.1728.org/mixture.htm
Scroll down to problem B
