Make x the subject of the equation: y=ax^2

x= ± sqrt [ y/a]

Step-by-step explanation:

y = ax^2

y/a = x^2

x^2 = y/a

x= ± sqrt [ y/a]

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

the answer is the third / last answer

step-by-step explanation: