20 points will be given!
for questions 1-4, find the interest. all rates are annual interest rates.
1.principal $400 rate 5% time 1 year
$10
$20
$40
$200
2.principal $1,000 rate 8.5% time 3 years
$255
$170
$22.5
$17
3. principal $200 rate 9% time 1/2 year
$9
$18
$36
$45
4. principal $20,000 rate 12% time 3 months
$240
$600
$800
$7,200
5. you borrow $1,200 at a rate of 4.5% for a period of 6 months. how much will you repay at the end of 6 months?
$240
$600
$800
$7,200

21 i watched a 3 hr vid explaining it

step-by-step explanation:

du what else would it be

brainliest

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!