Tuesday, September 7, 2010

1-3 Practice: Algebraic Expressions

1. seven less than the number "t" is t - 7
2. the sum of 11 and the product of 2 and a number "r" is 2r + 11
3. Arin has $520 and is earning $75 each week babysitting. Algebraic Expression is 520 +75w
4. You have 50 boxes of raisins and are eating 12 boxes each month. AE is 50 - 12m

Evaluate each expression using the given values of the variables:

5. -4v + 3(w + 2v) - 5w; v = -2 and w = 4

-4(-2) + 3 (4 + 2(-2)) - 5(4) = 8 + 3(0) - 20 = -12

10 comments:

  1. 6. c(3 - a) - c^2; a = 4 and c = -1
    -1 (3 - 4) - (-1)^2 = -1(-1) - 1 = 1 - 1 = 0

    7. 2(3e - 5f) + 3(e^2 + 4f); e = 3 and f = -5
    2[3(3) - 5(-5)] + 3[3^2 + 4(-5)] =
    2[9 - -25] + 3[9 - 20] = 2(34) + 3(-11) =
    68 - 33 = 35

    ReplyDelete
  2. Hey Lisa it's Fabiana. Im not sure how your blogs works but i'll just type my answers here.
    1. t-7
    2. 2r + 11
    3. 520 + 75w
    4. 50 - 12m
    5. -12
    6. 0
    7. 35
    8. 54
    9. 13.5
    10. 10.06
    11. 6.98
    12. 5x + 19x squared
    13. didnt understand
    14. 2t + t squared over 4
    15. -9a - 5
    16. -4j squared - 20k
    17. didnt understand
    18. 6(w) + 3(t) 1(g) w=winning t=ty g=goal
    second part 6(2w)+3(t)+1(5g)
    19. -42
    20. -224
    21. didnt understand
    22. 14x+y
    23. 15 - (-7x)
    24. didnt understand
    25. e
    26. d
    27. f
    28. b
    29. a
    30. c

    ReplyDelete
  3. -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

    ReplyDelete
  4. -2(j^2 - k) - 6(j^2 +3k)
    -2j^2 + 2k - 6j^2 - 18k
    - 8j^2 - 16k

    ReplyDelete
  5. Hi Lisa I have hw that I can use your help on. Its on word problems which I really dislike.
    I'll give you a few examples:

    1.Two brothers are saving money to buy tickets to a concert. Their combined savings is $55. One brother has $15 more than the other. How much has each saved?

    2. The sides of a triangle are in the ratio 5:12:13. What is the length of each side of the triangle if the perimeter of the triangle is 15 inches?

    3.Two trains left a station at the same time. One traveled north at a certain speed and the other traveled south at twice that speed. After 4 hours, the trains were 600 miles apart. How fast was each train traveling?

    I have more but thats a few

    ReplyDelete
  6. Hi There!

    When it comes to word problems, you need to figure out which information is useful and which doesn't matter. You also need to decide what question needs to be answered.

    So for the first example, they want to know how much each has saved. You need to define an equation for each brother and add those two equations together, the total being equal to $55.

    One brother is "x" and the other brother is "x + $15": x + x + 15 = 55. Once you solve for "x" you just need to plug the value for "x" into each of the (brother) equations.

    For the second example, you need to find the length of each side of the triangle. You are given the perimeter as 15 inches, which is the length of each side added together. So I would add 5x + 12x + 13x together equal to 15 inches. Then solve for "x" and plug your value for "x" back into each of the three sides' equations (5x, 12x, & 13x) and that will give you the lengths of the sides in inches.

    For example 3, think about the fact that speed is measured in miles per hour (Miles/hour). Let one train be "s" and the faster train be "2s". Add those together and multiply the sum by 4 hours. Next divide both sides to isolate the "s" variable and then plug that value back into the equations "s" and "2s" giving the speed of each train in miles per hour (miles/hour).

    ReplyDelete
  7. Example 1: one brother saved $20 and the other brother saved 20 + 15 = $35

    Example 2: The sides of the triangles are 2.5, 6, & 6.5 inches respectively

    Example 3: The formula should look like this
    4(s + 2s) = 600
    4(3s) = 600 --> 12s = 600 --> s = 50 mi. per hr.
    so one train went 50 mph and the other traveled at 100 mph.

    ReplyDelete
  8. In mathematics, an algebraic expression consists of variables, constants, operator signs (plus, minus, multiplication, division or exponentiation).

    ReplyDelete
  9. do you have an article about how to simplifying algebraic expression???

    ReplyDelete