Answer:
h (x)=-16x^(2)+3x+35 =
x-intercept(s): (3+√224932,0),(3−√2249 32,0)
y-intercept(s): (0,35)
So 161 divide 7 equals 23 so therefor he types 23 words per minutes. 23 times 20 equals 460. I think he can type 460 words in 20 minutes.
F(x)=x^2+3x+5
f(3+h)=(3+h)^2+3(3+h)+5
f(3+h)=9+6h+h^2+9+3h+5
f(3+h)=23+9h+h^2