Cynthia invests some money in a bank which pays 5% compound interest per year. She wants it to be worth over £8000 at the end of 3 years.
What is the smallest amount to the nearest pound, she can invest

£6956.52

Step-by-step explanation:

Given data

R=5%

A= £8000

T= 3 years

P=???

The compound interest is

A=P(1+r)^t

8000= P(1+0.05)^3

8000= P(1.05)^3

8000= P1.15

P= 8000/1.15

P=6956.52

Hence she needs to invest £6956.52

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb

hi there, i would be interested to you with your test, may you add the questions and answer options.

- : )