Question

Select all of the expressions that have a positive value

based on the positions of a and b.
(Select all that apply.)
X
-b
a+b
a-b
a b
-
b
a

Answer 1

To determine which expressions have a positive value based on the positions of a and b, we need to consider the signs of a and b and then evaluate each expression:

(-b) is positive if b is negative

(a+b) is positive if both a and b are positive or if a is negative and b is greater than the absolute value of a

(a-b) is positive if a is greater than b

(ab) is positive if both a and b have the same sign (either both positive or both negative)

(-b) is negative if b is positive

(a) is positive if a is positive

So, based on the positions of a and b, the expressions that have a positive value are:

(a+b), if both a and b are positive or if a is negative and b is greater than the absolute value of a

(a), if a is positive

Therefore, the correct answers are:

a+b

a