Question

Which expressions, when evaluated with y = –7, are positive in value?

Choose all answers that are correct.

A.
18 + 2y

B.
–3y + (–17)

C.
–2y – 23

D.
–30 – 4y

Answer 1

@pooja195

Answer 2

You can solve all of them by subbing the value of y with -7 OR
an easier way to do it is count the signs
two negatives make 1 positive so think of it as this:
Odd numbers of negative signs=negative solution
Even number of negative signs=postitve solution

Let's start with A
\[\huge~\rm~\bf~18 + 2(\color{red}{-7})\]

Answer 3

11

Answer 4

-7 * 2=?

Answer 5

-14

Answer 6

18-14=?

Answer 7

4

Answer 8

Good so A would be one of our answers...
Next lets try B
–3(-7) + (–17)
-3 * -7=?

Answer 9

10 and 21

Answer 10

We are multiplying so just 21
21-17=?

Answer 11

4

Answer 12

Good so we have A and B as our answers
Lets try C
-2(-7)-23=?

Answer 13

-23

Answer 14

-14-23 will result in a negative solution so C is incorrect lets try D
–30 – 4(-7)
-4*-7=?

Answer 15

28

Answer 16

good
-30+28=?

Answer 17

-2

Answer 18

Good so C and D can't be answers. Therefore our final answers are...?

Answer 19

a and b thx :)

Answer 20

yw ^_^