Answer:
See Explanation
Step-by-step explanation:
(a) Proof: Product of two rational numbers
Using direct proofs.
Let the two rational numbers be A and B.
Such that:


The product:




Proved, because 1/3 is rational
(b) Proof: Quotient of a rational number and a non-zero rational number
Using direct proofs.
Let the two rational numbers be A and B.
Such that:


The quotient:

Express as product



Proved, because 3/4 is rational
(c) x + y is rational (missing from the question)
Using direct proofs.
Let x and y be
Such that:


The sum:

Take LCM


Proved, because 7/6 is rational
<em>The above proof works for all values of A, B, x and y; as long as they are rational values</em>
D.A plane consist of an infinite set of lines.
Hi,
The answer is c. The sample is biased.
This is because the sample is taken on a single state, an Rebecca reports a statistic about the nation. Her data contains information only of her state. If she lives in a very cold state, there is probably more homeowners using electric heat than in a hot state.
Answer is B
total cost = $30 + 0.5 *(miles driven)
.................
4x3x = 12x
4x2 = 8
So 12x+8-2