Answer:
x=8
Step-by-step explanation:
3(x-10)=-6
3x-30=-6
3x=24
x=8
a = 4, b = -21, c = -18
to keep from getting "mixed up", evaluate the discriminant first ...
b<sup>2</sup> - 4ac = (-21)<sup>2</sup> - 4(4)(-18) = 729
sqrt(729) = 27
x = (21 +/- 27)/8
x = -3/4, x = 6
since the discriminant is a perfect square, the original quadratic will factor ...
4x<sup>2</sup> - 21x - 18 = 0
(4x + 3)(x - 6) = 0
x = -3/4, x = 6
Answer: k=9/4
Step-by-step explanation: We can do this by finding a number that adds up to 3 when multiplied by 2. The best way to do this is to use ((b^2)/4) which can usually find you the number for a perfect square based on b, which we have. So, 3^2 / 4 =9/4, meaning k=9/4. We can check:
>x^2 +3x +9/4
> (x+3/2)(x+3/2)
Perfect square.
I think maybe the answer is probably 7. Hope this helps !!