Math Homework Help?

In 1-5, evaluate the expression for the given x value, and desrcibe the order in which you performed the operations.

1. 3x + 15 when x = 12

2. 25 + 8x when x = 2

3. 10x - when x = 4

4. -3x + 10 when x = 7

5. 40 - 5x when x = 6

In 18-22, evaluate the expression for the given x value, and describe the order in which you performed the operations.

18. 7(x + 8) when x = -3

19. 7(5x + 8) when x = 3

20. 7 (8 - 5x) when x = 3

21. (8 - 5x) (3x + 2) when x = 10

22. (x + 5) (x+2) when x = 10

Duncan and Gish both used the equation to estimate the cost for 50 students. Duncan said the cost would be $10,500, and Gish said it would be $700.

a. Determine which estimate is correct. Show the calculations needed to find the estimate.

b.How do you think Duncan and Gish found such different estimates if they bith used the same questions?

Math Homework Help?sunshine

you should really do your own homeowork. it probably took more time to type it in than to actually do it.....

1.

3x + 15 when x = 12

SUBSTITUTION 3(12) + 15

MULTIPLICATION 36 + 15

ADDITION 51

2.

25 + 8x when x = 2

SUBSTITUTION 25 + 8(2)

MULTIPLICATION 25 + 16

ADDITION 41

3.

10x - when x = 4

i think you left out a number... but if not, then

SUBSTITUTION 10(4)

MULTIPLICATION 40

4.

-3x + 10 when x = 7

SUBSTITUTION -3(7) + 10

MULTIPLICATION -21 + 10

ADDITION -11

5.

40 - 5x when x = 6

SUBSTITUTION 40 - 5(6)

MULTIPLICATION 40 - 30

SUBTRACTION 10

18.

7(x + 8) when x = -3

SUBSTITUTION 7(-3 + 8)

ADDITION 7(5)

MULTIPLICATION 35

19.

7(5x + 8) when x = 3

SUBSTITUTION 7( 5(3) + 8)

MULTIPLICATION 7(15 + 8)

ADDITION 7(23)

MULTIPLICATION 161

20.

7(8-5x) when x = 3

SUBSTITUTION 7(8 - 5(3) )

MULTIPLICATION 7(8 - 15)

SUBTRACTION 7(-7)

MULTIPLICATION -49

21.

(8 - 5x) (3x + 2) when x = 10

SUBSTITUTION (8 - 5(10) ) ( 3(10) + 2)

MULTIPLICATION (8 - 50) (30 + 2)

SUBTRACTION / ADDITION (-42) (32)

MULTIPLICATION -1344

22.

(x + 5) (x + 2) when x = 10

SUBSTITUTION (10 + 5) (10 + 2)

ADDITION (15) (12)

MULTIPLICATION 180

i'm pretty sure you need an equation for the next one, so i can't help here. sorry!

i hope this helps!!

:)

Math Homework Help?star theater opera theater

1-5

1. 39

2. 41

3. 40

4. -11

5. 10

18-22

18. 35

19. 161

20. -49

21. -1344

22. 180
1.52

2.41

3.40

4. -4

5.10

18.35

19.161

20.-49

21.-1344

22.180

a)Gish's

b)one mutiplied and one added

im not so sure about a and b
1.) 3x+5; x=12 --%26gt; 3(12)+5

a: 36+5 = 37

2.) 25+8x, x=2 --%26gt; 25+8(2)

a: 25+16 = 31

3. 10x - when x = 4 --%26gt; 10(-4)

a: -40 (not sure what 10x- is)

4. -3x + 10 when x = 7 --%26gt; -3(7)+10

a: -21 + 10 = -11

5. 40 - 5x when x = 6 --%26gt; 40-5(6)

a: 40 - 30 = 10

18. 7(x + 8) when x = -3 --%26gt; 7(-3) + 8(-3)

a: -21 + -24 = -45

19. 7(5x + 8) when x = 3 --%26gt; 5(3)(7) + 8(7)

a: 15(7)+56 = 105+56 = 161

20. 7 (8 - 5x) when x = 3 --%26gt; 7(8)-5(7)(3)

a: 56-35(3) = 56-105 = -49

21. (8 - 5x) (3x + 2) when x = 10 --%26gt; [8-5(10)][3(10)+2)

a: (8-50)(30+2) = (-42)(32) = -1344

22. (x + 5) (x+2) when x = 10 --%26gt; (10+5)(10+2)

a: (15)(12) = 180

a. 50x = $10500 (Duncan); 50x=$700 (Gisha)

answer: x=$2,160 per student (Duncan)

x = $14 per student (Gisha)

b. I don't know how to answer that but the equation is #of students times x equals total cost.