X=21
-10x= -210
------- -------
-10 -10
X= 21
The line under the -10x and -210 is a division line you would divide -10x by -10 which would cancel out the -10 and divide -210 by -10 which when you divide a negative by a negative you would get a positive which leaves you with 21.
K(2)+2(-2)=k
2k-4=k
+4 +4
2k=k+4
-k -k
K=4
a) A line can intersect a parabola at 2 points, 1 point, or no points respectively. The only possible way at which it intersects at 1 point, would be if it were tangent to the parabola. [Check first attachment]
b) Two different parabolas can intersect at 2 points, 1 point or no points respectively. [Check second attachment]
It is possible for 2 parabolas to intersect at 4 and even 3 points. But one of the parabolas would be on it's side. You can consider those cases.
You want one of the values in the ratio to be one for a unit rate. First, write out the ratio. It is 70 miles/2 hours. It's better not to include decimal numbers when you write a ratio when you can, so we're going to make the hours the unit rate. To make 2 -> 1 hour, divide both sides of the ratio by 2. 70/2 = 35.
The unit rate is 35 mi./hr.
Hope that helped you.
