19. find the volume of a sphere with radius 9.25 cm. use 3.14 as an approximation for pi. round the answer to two decimal places.
a. 3313.55 cm3
b. 358.4 cm3
c. 1864.82 cm3
d. 114.08 cm3

20. evaluate: -16 minus w, when w = -23.
a. 7
b. -39
c. -7
d. 39

25. if ∠a and ∠b are complementary angles, and ∠a = 27°, find ∠b.
a. 63°
b. 65°
c. 70°
d. 73°

don't mind
the numbers
in the front

don't comment if you don't know or if your not sure need them all correct

let's add {f(x)=x+1}f(x)=x+1 and {g(x)=2x}g(x)=2x together to make a new function.

f(x)+g(x) =(x+1)+(2x)=x+1+2x=3x+1

let's call this new function hh. so we have:

{h(x)}={f(x)}+{g(x)}{=3x+1}h(x)=f(x)+g(x)=3x+1

we can also evaluate combined functions for particular inputs. let's evaluate function hh above for x=2x=2. below are two ways of doing this.

method 1: substitute x=2x=2 into the combined function hh.

h(x)

h(2)

​    

=3x+1

=3(2)+1

=7

​ since h(x)=f(x)+g(x)h(x)=f(x)+g(x), we can also find h(2)h(2) by finding f(2) +g(2)f(2)+g(2).

first, let's find f(2)f(2):

f(x)

f(2)

​    

=x+1

=2+1

=3

​  

now, let's find g(2)g(2):

g(x)

g(2)

​    

=2x

=2⋅2

=4

​  

so f(2)+g(2)=3+4=\greend7f(2)+g(2)=3+4=7.

notice that substituting x =2x=2 directly into function hh and finding f(2) + g(2)f(2)+g(2) gave us the same answer!