Question

Evaluate for the given values of the variables.

#17. 8 + 3n for n = 6
#18. (8 + 3)n for n = 6
#19. 90 - 4d for d = 3
#20. 7x + 2y for x = 15, y = 20
#21. sbt. for a = 2. b = 4
#22. 2 + 5x second power. for x = 4
#23. 2 + (5x) second power. for x = 4
#24. (2 + 5x) second power. for x = 4

Answer 1

#17

`\rm8 + 3n \: for \: n = 6`

`8 + 3(6)`

`8 + 18`

`26`

#18

`\rm(8 + 3)n \: for \: n = 6`

`\rm(8 + 3)n`

`\rm(11)n`

`(11)(6)`

`66`

#19

`\rm90 - 4d \: for \: d = 3`

`90 - 4(3)`

`90 - 12`

`78`

#20

`\rm7x + 2y \: for \: x = 15 \: and \: y = 20`

`7(15) + 2(20)`

`105 + 40`

`145`

#23

`\rm2 + (5x {)}^(2) \: for \: x = 4`

`2 + (5(4 {))}^(2)`

`2 + {(20)}^(2)`

`2 + 400`

`402`

#24

`\rm(2 + 5x {)}^(2) \: for \: x = 4`

`(2 + 5(4) {)}^(2)`

`(2 + 20 {)}^(2)`

`{(22)}^(2)`

`484`

Answer 2

17) 26

18) 66

19) 78

20) 145

Explanation:

#17) 8 + 3n for n = 6

8 + 3*(6)

8 + 18 = 26

#18) (8 + 3)n for n = 6

(8 + 3)*6

(11)*6 = 66

#19) 90 - 4d for d = 3

90 - 4*(3)

90 - 12 = 78

#20) 7x + 2y for x = 15, y = 20

7*(15) + 2*(20) = 145