Answer:
C
Step-by-step explanation:
Multiply the top and bottom, both by sqrtx-sqrt5. This is in order to rationalize the denominators.
You get answer C.
A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 20 is about 4.472. Thus, the square root of 20 is not an integer, and therefore 20 is not a square number.
Answer:
110 degrees
Step-by-step explanation:
it is 110 degrees because on a line comebinedt is 180 degrees. And you already ahve one side which is 70 degrees. So 180 minus 70 is 110 degrees.
Four times the sum of n plus six
Answer:
15 seconds
Step-by-step explanation:
If you make a table of values for the dog and the squirrel using d = rt, then the rates are easy: the dog's rate is 150 and the squirrel's is 100. The t is what we are looking for, so that's our unknown, and the distance is a bit tricky, but let's look at what we know: the dog is 200 feet behind the squirrel, so when the dog catches up to the squirrel, he has run some distance d plus the 200 feet to catch up. Since we don't know what d is, we will just call it d! Now it seems as though we have 2 unknowns which is a problem. However, if we solve both equations (the one for the dog and the one for the squirrel) for t, we can set them equal to each other. Here's the dog's equation:
d = rt
d+200 = 150t
And the squirrel's:
d = 100t
If we solve both for t and set them equal to each other we have:

Now we can cross multiply to solve for d:
150d = 100d + 20,000 and
50d = 20,000
d = 400
But we're not looking for the distance the squirrel traveled before the dog caught it, we are looking for how long it took. So sub that d value back into one of the equations we have solved for t and do the math:

That's 1/4 of a minute which is 15 seconds.