x=4 because if you add 7 to 10 you get -2x-3=-14x then you add -2x to -14x and you get -3=-12 then you divide by -3 and -12 to get 4
It will be 21/40
probability getting both white marbles
3/8×4/10=12/80
probability getting both black marbles
5/8×6/10=30/80
12/80+30/80=42/80= 21/80
Answer:
By calculating the profit that will keep the business going
They are variables they can equal anything. it is just an example of two different fractions who's numbers are unknown.
Answer:

Step-by-step explanation:
![\dfrac 12 \left[\sin(a+b)+\sin(a-b) \right]\\\\\\=\dfrac 12\left[ 2 \sin a \cos b\right]\\\\\\=\sin a \cos b](https://tex.z-dn.net/?f=%5Cdfrac%2012%20%5Cleft%5B%5Csin%28a%2Bb%29%2B%5Csin%28a-b%29%20%5Cright%5D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%2012%5Cleft%5B%202%20%5Csin%20a%20%5Ccos%20b%5Cright%5D%5C%5C%5C%5C%5C%5C%3D%5Csin%20a%20%5Ccos%20b)