What is eighty one raised to the - 3/4 power

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

Which of the following functions corresponds to the above sinusoid? a. 10 cos πx - 5 b. -5 sin x - 5 c. -10 cos πx/2 - 0.5 d. 10 sin πx - 5

What are two numbers that add up to -9 and multiply to -10 best answer gets branliest and 100 extra points