Solve each system by elimination 9) 5x+y=9 10x-7y=-18

x=1, y=4

Step-by-step explanation:

5x+y=9

10x-7y=-18

To solve by elimination, we pick a variable to eliminate, or get rid of.  I will multiply the first equation by -2 so we can get rid of x

-2( 5x+y)=9 *-2

-10x -2y = -18

Now we add this equation to the second equation

-10x -2y = -18

10x-7y=-18

-9y = -36

Divide each side by -9

-9y/-9 = -36/-9

y =4

We still need to solve for x

5x+y=9

Put in y=4

5x+4 = 9

Subtract 4 from each side

5x +4-4 = 9-4

5x = 5

Divide each side by 5

5x/5 = 5/5

x=1

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.