need help with 2325 38 39 40 41 need help with 42 43 44 45 4

2-2 You can combine like terms and use the Distributive Property to simplify expressions and solve equations Solve each equation. 17. b + 4b--90 19. 2( +5)-9 21.x-(4-x) =0 23. sson use the Distributive perty when combining e terms (p. 76) use the Distributive perty when solving ations (p. 77) 18. -x 7x24 20),-(3-10y)-12 22. 4n + 7+6n 32 24. 0.36p + 0.26 3.86 alg1 2.0, 4.0, 5.0 25. The width of a rectangle is 6 cm less than the length. The perimeter is 72 cm. Write and solve an equation to find the dimensions of the rectangle 2-3 ve equations with les on both sides You can use the properties of equality to solve an equation with variables on both sides An equation has no solution if no value of the variable makes the n equation true. An equation is an identity if every value of the variable makes the equation true. tify equations that ntities or have no n (p. 86) Solve each equation. 27. 4(5x -2)-6x- 5(2x+ 4) 29,5(3-d)=2d + 1 1 4.0, 5.0, 25.3 28. 3(2t -6) 3-9 28,3(2-6) = 3r-9 30.12(h-1) = 6h + 4 + 2h Determine whether each equation is an identity or whether it has no solution. 32. 4h + 7 = 4h-3 34.-Sa-7+4a=-(a-7) . Use an equation to solve each problex 36. One online bookstore charges $20 per bonic ane $8 lee shipping. Another online bookstore charges $12 per book and offers free shipping. For what number of books is the cost the same? 37. A cable company charges $39.95 per month for basic cable service and $8.95 per month for each premium channel. If Derek\'s monthly bill is $66.80, how many premium channels does he receive? A ratio is a comparison of two numbers by division. A rate is a ratio that compares quantities measured in different units. A proportion is a statement that two ratios are equal. You can solve a proportion involving a single variable by finding the cross products sand rates ortions Write in miles per hour. Round to the nearest tenth where necessary 38. 2.5 mi/min 40. 4 inJs 15.0, 25.0 ry. 39. 300 ft/min 41. 130 ft in 12.5 s

Solution

23 ) ( 3y/4 ) - ( y/2 ) = 5

Take L.C.M of denominators

( 3y - y.2 ) / 4 = 5

3y -2y = 20

y = 20

25 ) Given that

The width of rectangle is 6cm less than its length

Let    Length = xcm

width = x - 6 cm

Perimeter of rectangle = 72 cm

We know that,

  Perimeter of rectangle = 2( length + width)

Hence,

  2( length + width) = 72

2 ( x + x - 6 ) = 72

2 ( 2x - 6 ) = 72

2x - 6 = 72/2

2x - 6 = 36

2x = 42

x = 42/2

x = 21

Length = 21 cm

Width = x - 6

= 21 - 6 = 15

Width = 15

38 ) convert into miles/hour

2.5 mi/min = 2.5 x 60 [ since,1 mile/min = 60 milee/hour ]

= 150 mi/hour

39 ) 300 ft /min = 300 x 0.0113636 [ since, 1 ft/min = 0.0113636 miles/hour ]

= 3.40908

= 3.4 miles/hour

40 ) 4 in./sec = 4 x 0.568181818 [since, 1 in/sec = 0.568181818 ]

= 2.272727272

= 2.3 miles/hour

42 ) 4/12 = c/6

( 4/12 ) x 6 = c

24/12 = c

c = 2

43 ) t/5 = 23/50

t = ( 23/50 ) x 5

t = 23/10

t = 2.3

44 ) -9/m = 3/2

1/m = ( 3/2 ) x (-1/9)

1/m = -1/6

m = -6

45 ) x / 8 = ( x - 5 ) / 6

  x / 8 - ( x - 5 ) / 6 = 0

Take L.C.M of denominators

[ 3x - 4(x-5) ] / 24 = 0

[ 3x - 4x + 20 ] = 0

-x + 20 = 0

-x = - 20

x = 20

46 ) 12 / r = 4 / (0.5r-1)

Apply cross multiplication

12 ( 0.5r - 1 ) = 4r

6r - 12 = 4r

6r - 4r = 12

2r = 12

r = 6

47 ) ( d - 2 ) / ( d + 9 ) = 3/14

Apply cross multiplication

( d - 2 ) x 14 = ( d + 9 ) x 3

14d - 28 = 3d + 27

14d - 3d = 27 + 28

11d = 55

d = 55/11

d = 5