Question

A number line is shown below. The numbers 0 and 1 are marked on the line, as are two other numbers a and b.

Which of the following numbers is negative? Choose all that apply. Explain your reasoning.

a+(-1)




a+(-2)




-b



a+b




a+(-b)

Answer 1

a−1 : positive

a−2 : negative

−b : positive

a+b : negative

a−b : positive

ab+1 :negative

Explanation:

a−1 :a is greater than 1, so a−1 is positive

a−2 : b a−2 is negative

−b :−b is positive

a+b : Since b is negative and a is positive, a+b is negative

a−b : also positive. a−b is positive

ab+1 :ab+1 is negative.