-2x^2+6x+15≤0 solve by product method
4 answers
See answer
For seen the answer
Tell me the answer
impatient much?
stop whining and
(a) try to solve it yourself
(b) wait for someone who can to help.
-2x^2+6x+15 does not factor using rational numbers, so the product ,ethod seems kind of useless here.
the quadratic formula gives the roots as x = (3±√39)/2
completing the square gives
-2x^2+6x+15 = 0
2x^2 - 6x = 15
2(x^2 - 3x + 9/4) = 15 + 9/2
2(x - 3/2)^2 = 39/2
x - 3/2 = ±√39/2
x = (3±√39)/2
you can google the product method for examples, but they probably will not help much.
In any case, now that you have the roots, and knowing the shape of a parabola, you can see that the solution set is
x <= (3-√39)/2 or x >= (3+√39)/2
stop whining and
(a) try to solve it yourself
(b) wait for someone who can to help.
-2x^2+6x+15 does not factor using rational numbers, so the product ,ethod seems kind of useless here.
the quadratic formula gives the roots as x = (3±√39)/2
completing the square gives
-2x^2+6x+15 = 0
2x^2 - 6x = 15
2(x^2 - 3x + 9/4) = 15 + 9/2
2(x - 3/2)^2 = 39/2
x - 3/2 = ±√39/2
x = (3±√39)/2
you can google the product method for examples, but they probably will not help much.
In any case, now that you have the roots, and knowing the shape of a parabola, you can see that the solution set is
x <= (3-√39)/2 or x >= (3+√39)/2