Sam received $1120 interest from his 4 year investment at 3.5% p. a. simple interest. how much did sam invest? .

$8000

Step-by-step explanation:

The method for calculating simple interest (I) is

I =

where P is the principal, R is interest rate, T is time in years

here I = 1120, R = 3.5, T = 4 and P is to be found, thus

1120 = ( multiply both sides by 100 )

3.5 × 4 × P = 112000

14P = 112000 ( divide both sides by 14 )

P = = $8000

-3

step-by-step explanation:

a drawing really does here:

so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be).   so point b is at (-2,2).   point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).

now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.

we have the area of the triangle is .5bh=12.5

we know the base length is 5 (ab)

we have the height is (2-y) if you look at your

plug in

.5(5)(2-y)=12.5

solve for y to get the y-coordinate for c

2.5(2-y)=12.5

divide both sides by 2.5 giving:

2-y=5

now subtract 2 on both sides

-y=3

y=-3