Method A: If we count, we see that the answer is 31.
Method B: 19 - -12 = 31. We can even do -12 - 19 and we'll get the same answer: -31, and the absolute value of -31 is 31.
Both methods will give you the same answer.
The line is parallel to x-axis
the correct answer -
y = –4
If we know your Pythagorean Triples we can immediately recognize that the last choice is a right triangle:
8² + 15² = 17²
If you don't know your Pythagorean Triples, it's worth learning the first few off the list because teachers use them in problems all the time. But for now let's just exhaustively check the Pythagorean Theorem for each triangle. We don't have to multiply everything out; we can analyze the common factors. If two have a common factor that the third one doesn't have, there's no way for the Pythagorean Theorem to add up.
Clearly 5²+15² is a multiple of 5 but 18² isn't so that one isn't a right triangle.
6²+12² is a multiple of 6, 16² isn't a multiple of 6, not an RT.
15²-5² is a multiple of 5, 13² isn't, no joy.
8²+15² = 64 + 225 = 289 = 17² -- that's a real right triangle, a valid Pythagorean Triple.
Answer: D
Step-by-step explanation: get the variable by itself on one side of the inequality sign.
Answer: Aproximately 2,525 balloons
Step-by-step explanation:
1. Find the volume of a balloon with the formula given in the problem, where 
is the radius (
), then:
2. Convert the volume from m³ to lliters by multiplying it by 1,000:
3. You know that that 1 liter of helium can lift 1 gram and that Ryan weighs 5 stone and 5 pounds. So you must make the following conversions:
1 g=0.0022 lb
From 5 stones to pounds
4. Then Ryan's weigh is:
5lb+70lb=75lb
5. Then, if 1 liter of helium can lift 0.0022 lb, to lift 75 lb (which is the weight of Ryan) they need:
6. Then, to calculate the aproximated number of balloons they need to make him float (which can call 
), you must divide the liters of helium needed to lift the weight of Ryan by the volume of a balloon, then the result is:
≈2,525 balloons.
