Question

Which expression has a value that is equivalent to 5n + 13 when n=−5 ?

2n + 2
n + 8
4n + 8
n² + 13

Answer 1

5n + 13.....n = -5
5(-5) + 13 =
-25 + 13 =
-12

4n + 8.....n = -5 <===
4(-5) + 8 =
-20 + 8 =
-12

Answer 2

First we will calculate the value of expression
`5n+13` when n= -5

`5n+13`

=
`(5 * -5)+13`

= -25+13

= -12.

Now, we will calculate the value of each expression at n=-5

1. 2n+2

=
`2 *(-5)+2`

= -10+2 = -8, which does not have the equivalent value of the given expression.

2. n+8

= -5+8

= 3,which does not have the equivalent value of the given expression.

3. 4n+8

=
`4 * (-5)+8`

= -20+8

= -12 , it has the equivalent value of the given expression.

4.
`n^(2)+13`

=
`(-5)^(2)+13`

= 25+13

= 38,which does not have the equivalent value of the given expression.

Therefore, expression 3 has a value that is equivalent to 5n + 13 when n=−5.