5x+4y=20.14
6x+7y=28.15

x=2.2582, y=19.91/9. (2.2582, 19.91/9).

Step-by-step explanation:

5x+4y=20.14

6x+7y=28.15

6(5x+4y)=6(20.14)

-5(6x+7y)=-5(28.15)

30x+24y=120.84

-30x-35y=-140.75

-9y=-19.91

9y=19.91

y=19.91/9

5x+4(19.91/9)=20.14

5x+79.64/9=20.14

5x=20.14-79.64/9

5x=11.291

x=11.291/5

x=2.2582

ab will be equal to

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.