"Dividing<span> by </span>fractions<span> is just like multiplying </span>fractions<span>, except for one additional step. To </span>divide<span> any number by a </span>fraction<span>: First step: Find the reciprocal of the </span>fraction<span>. Second step: Multiply the number by the reciprocal of the </span>fraction<span>." -Google</span>
The awnser of the question is B

The multiples of 105 are 3,5,and 7 so none of them can come out of the square root so it cannot be simplified.
Expanding the limit, we get (x^2+2x∆x+∆x^2-2x-2∆x+1-x^2+2x-1)/<span>∆x
Crossing the 1s , the 2xs, and the x^2s out, we get
(2x</span>∆x+∆x^2-2∆x)/<span>∆x
Dividing the </span><span>∆x, we get
2x+</span><span>∆x-2.
Making the limit of </span><span>∆x=0, we get 2x-2.</span>
10+5x=50
subtract ten from both sides
5x=40
divide five from both sides
x=8
samuel will need to paint 8 additional rooms