The equations in this system were added to solve for y. What is the value of y? X + 6 y = 10. Minus x + 3 y = negative 15. Equals 9 y = negative 5. Y = Negative StartFraction 9 Over 5 EndFraction y = Negative StartFraction 5 Over 9 EndFraction y = StartFraction 5 Over 9 EndFraction y = StartFraction 9 Over 5 EndFraction

y = StartFraction 5 Over 9 EndFraction

y=5/9

Step-by-step explanation:

Given:

x+6y=20

-x+3y=-15

x+6y=20. (1)

-x+3y=-15 (2)

From (1)

x=20-6y

Substitute x=20-6y into (2)

-x+3y=-15

-(20-6y)+3y = -15

-20+6y+3y = -15

9y=-15+20

9y=5

Divide both sides by 9

9y/9=5/9

y=5/9

y = StartFraction 5 Over 9 EndFraction

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you

3

step-by-step explanation:

because where the point where the 2 lines intersect is (3,-1) the x value is 3