Suppose a, b, and c are integers. Prove that if a | b, then a | bc. Suppose a, b, and c are integers. Prove that if a | b and a | c then a | b + c and a | b-c.

The answer is not clear enough, please write in a way that can be read because I only have one try to submit.

8 + 2x - 3x2 for -2 ≤ x ≤ 3.

4x − 7 ≤ 9

You need to be reimbursed for the 36 light bulbs you bought. Unfortunately, the receipt is smudged andyou can only read $x82.5y where the spacing tells you that x and y are digits. You are sure that thebulbs were less than $15 each. How much did they cost? Use congruences to determine your answers.Show all the necessary work to obtain your answer.

? = 6; ? = 2 P(5 ≤ x ≤ 8)