Create an equivalent of the quadratic function of f(x)=-x/2+10x-18

The difference of 2 numbers is 21 and the quotient of the equation is 4 then what are the two numbers?

5. (04.07)which of the following exponential functions goes through the points (1, 12) and (2, 36)? (2 points)f(x) = 3(4)^xf(x) = 4(3)^-xf(x) = 3(4)^-xf(x) = 4(3)^x

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.