Answer and Step-by-step explanation:
(a) Given that x and y is even, we want to prove that xy is also even.
For x and y to be even, x and y have to be a multiple of 2. Let x = 2k and y = 2p where k and p are real numbers. xy = 2k x 2p = 4kp = 2(2kp). The product is a multiple of 2, this means the number is also even. Hence xy is even when x and y are even.
(b) in reality, if an odd number multiplies and odd number, the result is also an odd number. Therefore, the question is wrong. I assume they wanted to ask for the proof that the product is also odd. If that's the case, then this is the proof:
Given that x and y are odd, we want to prove that xy is odd. For x and y to be odd, they have to be multiples of 2 with 1 added to it. Therefore, suppose x = 2k + 1 and y = 2p + 1 then xy = (2k + 1)(2p + 1) = 4kp + 2k + 2p + 1 = 2(kp + k + p) + 1. Let kp + k + p = q, then we have 2q + 1 which is also odd.
(c) Given that x is odd we want to prove that 3x is also odd. Firstly, we've proven above that xy is odd if x and y are odd. 3 is an odd number and we are told that x is odd. Therefore it follows from the second proof that 3x is also odd.
Yes, both of your answers are correct.
Since Death Valley is below sea level, the hiker increases altitude before stopping at 0 feet.
Percent of increase is given by the formula (amount of change)/(original amount) * 100. Your work is accurate.
D) There is no association between commuting preferences and gender.
Answer:
c = 12.73
Step-by-step explanation:
a^2 + b^2 = c^2
9^2 + 9^2 = c^2
81 + 81 = c^2
162 = c^2
c = 
c = 12.7279221
c = 12.73
Mark brainliest please!
there's not enough information to solve