Algebra 1 Common Core Student Edition, Grade 8-9

(Marvins-Underground-K-12) #1
Q Apply


Solve each equation. Check your answer.

38.^2 + y

41-2 2C

44.^ = 5±


  • 2
    39. -2 4 = -101+3

42 x ~ 3 = — 4 I
3 2

  1. 2.4 + 10m = 6.89
    40. 10 = 0.3x — 9.1
    43. 9.4 = —d + 5.6
    46. 3= -17

Solve each equation. Justify each step.

  1. 15 = 9 - 3p 48. 4 — 5fc = - 1 6 49. 9 +^35 = -5 50.

5 1. E rro r A n alysis D escribe an d correct the error in finding th e solution of the
equation at th e right.

  1. W riting W ithout solving th e eq u a tio n - 3 x + 5 = 44, tell w h e th e r th e value of x is
    positive or negative. How do you know?

  2. a. Solve th e equ atio n^2 x -^1 = 7 by un d o in g subtraction first.
    b. Solve th e equ atio n in p a rt (a) by un d o in g m ultiplication first. Do you get the
    sam e answ er you got in p a rt (a)?
    c. R easo ning W hich m eth o d from p arts (a) a n d (b) do you prefer? Explain.

Geometry In each triangle, the measure of LA equals the measure of LB. Find
the value of x.

12 = 2

  1. Think About a Plan A Web site allows m usicians to p ost th eir songs online. Then
    people using th e Web site can buy any of th e p o sted songs. Suppose each m usician
    m u st pay a o ne-tim e fee of $5 to use the Web site. Each m usician earns $.09 every
    tim e a p articular song of his or hers is dow nloaded. If a m usician ea rn ed $365 for a
    particular song, how m any tim es was the song dow nloaded? \
    . • How can th e m odel at th e right help you solve th e problem?

  • How does the m odel tell you w hich operations to use in the equation?

  1. Open-Ended Write a real-w orld problem th a t you can m odel w ith the tw o-step
    equation 8b + 6 = 38. Then solve th e problem.

  2. Home Im provem ent A contractor is adding a back p orch on to a house. The porch
    needs to h old 20 people a n d furniture th a t weighs 250 lb. The contractor calculates
    th a t th e p orch n eeds to hold 3750 lb to m eet th a t specification. W hat value did the
    contractor use for the w eight of a person?


92 Ch ap t er 2 So l v i n g Eq u a t i o n s

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