SOLUTION: What is the solution of: -x^2+x>=-20? Answer choices: A) x<=-4 or x>=5 B) -4<=x<=5 C) x<=-5 or x>=4 D) -5<=x<=4

Question 132830: What is the solution of: -x^2+x>=-20?
Answer choices:
A) x<=-4 or x>=5
B) -4<=x<=5
C) x<=-5 or x>=4
D) -5<=x<=4
Answer by nycsharkman(136) (Show Source): You can put this solution on YOUR website!
What is the solution of: -x^2+x>=-20?
Answer choices:
A) x<=-4 or x>=5
B) -4<=x<=5
C) x<=-5 or x>=4
D) -5<=x<=4
=================
-x^2 + x >= - 20
Bring +20 to the left side.
-x^2 + x + 20 = >= 0
-x^2 + 5x - 4x + 20 >= 0
Set into groups:
x(-x + 5) 4(-x + 5) >= 0
(x + 4) (-x + 5) > = 0
Set each factor to zero and solve for x.
x + 4 >= 0
x >= - 4
==========
NEXT:
-x + 5 >= 0
-x >= -5
We now divide both sides by -1, which is the coefficient of x.
However, when we divide by a negative number, we MUST reverse the sign of the inequality.
x <= 5
We have this solution for x:
x >= - 4
x <= 5
Final answer: Choice B
Is this clear?

RELATED QUESTIONS
Which solution set satisfies the absolute value function:|x-3|- 5 ≤ 2? Answer... (answered by Edwin McCravy)

Without graphing, find the line of symmetry. The answer is either A,B,C,or D. I got... (answered by stanbon)

If 3x - 4y = 5, then what is the value of y/3 - x/4? Answer Choices: a) 5 b) -5/12... (answered by Boreal)

Find all solutions to the equation |2x-1| -2=7 A) x=-5 or x=4 B) x=5 or x=-5 C) x=3 or (answered by eversteen)

i need a little help to make sure i am doing this right. Solve: 2x-5=(the square root... (answered by jim_thompson5910)

What are the solutions to the equation |x - 3| = 14? A. x = 11 or x = 17 (answered by ewatrrr)

If {{{ ln(x^2) - 16 <= ln(4x - 11) }}} then which one of the following condition is... (answered by greenestamps)

Questions: (x-5) (x+6)/ x-4 <0 Possible Answers: (a) x<-6 or 4 (answered by sdmmadam@yahoo.com)
A = {x | x < 1}, B = {x | x ≥ 5}, and C = {x | x = 5}, match the following items. (answered by stanbon)