I need help solving these problems
y=-0.4x^2+8.3x+4.3 I got 0.52
h=-16t^2+149t+30 I got 640.5 feet after 4.63 seconds
0=x^2+3x-10 I got x=5, -2
(2x-4)(2x-1)=0 I got -2, 1/2
x^2+8x=10 I got -1.1, 9.1
HELP PLEASE
Type in your function here, and it will give you the roots and other info.
http://www.wolframalpha.com/input/?i=-0.4x%5E2%2B8.3x%2B4.3
On this one,
x^2+3x-10 = 0
you should have factored it:
(x+5)(x-2) = 0
Then you would have seen that the roots are -5 and 2, rather than what you wrote.