Mr. Warren Buffett invested $20 000. Part of it he put in the bank at 5% interest. Part of it he invested in bonds which pay a 7% return. How much money did he put in each vehicle, if his annual income from these
investments was $1200?

Vehicle one he put $10000

Vehicle two he put $1000

Step-by-step explanation:

Interest= PRT/100

Interested= x

P1 +P2= $20000

X1+x2= $1200

R1= 5%

R2= 7%

(P1*5*1)/100= X1

5p1=100 X1

P1= 20X1...

(P2*7*1)/100= X2

7p2= 100X2

P2= 100/7 X2

P1 +P2= $20000

20X1 + 100/7 X2= 20000

7X1 +5x2= 7000...equation one

X1+x2= 1200 equation two

Multiplying equation two with 7

7X1 +7X2= 8400

7X1 +5x2= 7000

Solving simultaneously

2X2=1400

X2= 700

P2= 100/7 X2

P2= 100/7 (700)

P2= 10000

But X1+x2= $1200

X1= 1200-700

X1= 500

P1= 20X1

P1= 20(500)

P1= 10000

Vehicle one he put $10000

Vehicle two he put $1000

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺

he answer is x=1x3 because x=1 to x=3