1. What are the roots of the equation?

5x^3+45x^2+70x=0

A. {−7, −2, 0}

B. {−7, 0, 2}

C. {0, 2, 7}

D. {−2, 0, 7}

2. What number needs to be added to both sides of the equation in order to complete the square?

x^2−18x=17

The file attached below is for question #2

1 What are the roots of the equation 5x345x270x0 A 7 2 0 B 7 0 2 C 0 2 7 D 2 0 7 2 What number needs to be added to both sides of the equation in order to compl class=

Respuesta :

1) A. since, if you put the numbers into the equation (one at a time) the equation = 0 each time, which is true.
2) I think I've been taught to complete the square slightly differently
x^2 - 18x - 17 = 0
(x-9)^2 - 81 -17 = 0
(x-9)^2 - 98 = 0
I hope you can get something from that

1. factor the left side, divide all terms by 5x, solve all x's for 0

answer is A. {−7, −2, 0}


2. you would need to add (-9^2) to both sides.  -9^2 = 81, so add 81 to both sides