What is the value of y if (3,y) is a solution to the equation 5x-3y=18

(x, y) → (3, y) → x = 3

Put the value of x to the equation:

5(3) - 3y = 18

15 - 3y = 18     subtract 15 from both sides

-3y = 3    divide both sides by (-3)

y = -1

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18