16x^4-81y^4 difference of perfect squares...
(4x^2-9y^2)(4x^2+9y^2) that's one of the equivalents...
(2x+3y)(2x-3y)(4x^2+9y^2) that's another one of them...
Answer:
16.
Step-by-step explanation:
The whole numbers stay the same so it stays as 2. The way they get 30 for the denominator is by multiplying the fraction 1/3 by 10 and 1/5 by 6. So now we have 10/30 and 6/30. Add them together, 10+6=16
Answer:
165 cards left
Step-by-step explanation:
x + 221 = 386
-221 from both sides
x = 165
You can verify this by plugging the numbers into the Pythagorean theorem,

, where c is the hypotenuse (the longest side, in this case 53).
So it would be:

The equation is true.
2809 = 2809
Answer:
Step-by-step explanation:
Domain is all the x's and range is all the y's. There's no reason why you couldn't pop any x into the given equation and calculate it and get a number out. So literally ANY x can be used and found on this graph. So the domain is all real numbers, one of the first two answers is going to be the right one. Now, the range is all the y's on the graph. The problem says that the parabola opens down, which means it has a highest point. There is no graph above that point. That's the point (-1, 16). So 16 is the highest y-value you can find on the graph. All the rest of the y's are smaller. The range is all the y's such that the y's are 16 and smaller...in math that's written {y | y <= 16} So the second answer is the right one.