Which statement describes the first step to solve the equation by completing the square?

3x^2+18x=21

Multiply both sides of the equation by 19 .

Add 9 to each side of the equation.

Multiply both sides of the equation by 13 .

Add 81 to each side of the equation.

the rocket cannot penetrate the ground, in a contextual sense, therefore the roots of this equation should be the domain of this function. i'll let you find the roots of this quadratic equation (hint: use the quadratic formula:  

1- c

2-a

step-by-step explanation:

mark brainliest!

5

10

15

20

25

30

35

40

45

50

55

the domain of a function is the set of input values, x , for which a function is defined. the domain is shown in the left oval in the picture below. the function provides an output value, f(x) , for each member of the domain.