58. In nine given numbers, the average of first five numbers is 20 and that of the last five numbe also 20. If the average of mine numbers is 16. what is the fifth number?​

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Erinn wrote the equation –5x + 4y = 32 to represent her hourly wage (y) and how this wage has changed during each year that she worked at a company (x). what is the rate of change in erinn's hourly wage per year?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ac=26 and ch=8, find bh.