Mr. jones has part of his $5,000 savings in an account that earned 7% interest and the rest in an account that earned 9% interest. how much did he have in each account if his annual income from the total investment was 404.27? use z for the 7% account and y for the 9% account.

z = $2286.5

y = $2713.5

Step-by-step explanation:

Let z represent the amount of money invested at the rate of 7%.

Let y represent the amount of money invested at the rate of 9%.

Mr. Jones has part of his $5,000 savings in an account that earned 7% interest and the rest in an account that earned 9% interest.. This means that

z + y = 5000

The formula for simple interest is expressed as

I = PRT/100

Where

P represents the principal

R represents interest rate

T represents time

Considering the investment at the rate of 7%,

P = x

R = 7

T = 1

I = (z × 7 × 1)/100 = 0.07z

Considering the investment at the rate of 9%,

P = y

R = 9

T = 1

I = (y × 9 × 1)/100 = 0.09y

if his annual income from the total investment was 404.27, it means

0.07z + 0.09y = 404.27 - - - - - -1

Substituting z = 5000 - y into equation 1, it becomes

0.07(5000 - y) + 0.09y = 404.27

350 - 0.07y + 0.09y = 404.27

- 0.07y + 0.09y = 404.27 - 350

0.02y = 54.27

y = 54.27/0.02 = $2713.5

Substituting y = 2713.5 into z = 5000 - y, it becomes

z = 5000 - 2713.5 = $2286.5

answer: the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

step-by-step explanation:

the given rate of interest i= 85%

in calculating the monthly payment for a loan with an interest rate compounded monthly, the value of the interest rate per period we use in the formula must be in decimal form.

to convert it in decimal, we divide it by 100, we get

hence, the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4