Mr B has $20000 to invest. He invests part at 6% and the rest at 7%. He earns $1280 interest. How much did he invest at each of the rates?

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6

6

6

6

6

6

6

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6

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6

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6

66answer:

step-by-step explanation:

the correct answer is 5 6 and 7

option c) graph of line going through 1, 4 and 3, 10

step-by-step explanation:

let y equal to margo's coin collection

let x equal to number of years

at the begining x=0, y=1 → point=(x,y)→point=(0,1)

she adds 3 coins per year, then y=1+3x

at x=1, y=1+3(1)=1+3→y=4→point=(x,y)→point=(1,4)

at x=3, y=1+3(3)=1+9→y=10→point=(x,y)→point=(3,10)

the graph of line going through (1, 4) and (3, 10), then the option c is the correct.