Solve by Factoring:

-0.125x^2+1.75x+7=0

let's first of all get rid of those nasty decimals

multiply by 1000
-125x^2 + 1750x + 7000 = 0
now divide everyboyd by -25
5x^2 - 70x - 280
even better
x^2 - 14x - 56 = 0
and after all that, it doesn't factor
How about completing the square ??

x^2 - 14x + 49 = 56 + 49
(x-7)^2 = 105
x-7 = ± √ 105
x = 7 ± √105

the answer is correct, I tested by subbing into original