(322) 68. P h y s i o l o g y T h e r e c o m m e n d e d h e a r t ra te f o r e x e rc is e , i n b e a ts p e r m in u t e , is g iv e n
b y th e e x p r e s s io n 0 .8 (2 0 0 - y ) w h e r e y i s a p e r s o n ' s a g e i n y e a r s. R e w r i t e t h i s
e x p r e s s io n u s in g t h e D is t r ib u t iv e P r o p e r ty. W h a t is th e r e c o m m e n d e d h e a r t ra te f o r
a 2 0 - y e a r - o ld p e rs o n? F o r a 5 0 - y e a r - o ld p e r s o n? U s e m e n t a l m a th.
- Error Analysis I d e n t i f y a n d c o r r e c t t h e e r r o r
s h o w n a t t h e r ig h t. - Error Analysis A f r ie n d u s e s t h e D is t r ib u t iv e P r o p e r ty t o s im p lif y
4{2b — 5 ) a n d g e ts 8b — 5 as the result. Describe and correct the error.
Geometry Write an expression in simplified form for the area of each rectangle.
- 11 5 + 2 y
73.
3x+ 2 5 5n - 9
- Think About a Plan Y o u a re r e p la c in g y o u r r e g u la r s h o w e r h e a d w it h
a w a te r - s a v in g s h o w e r h e a d. T h e s e s h o w e r h e a d s u s e th e a m o u n t
o f w a t e r p e r m i n u t e s h o w n. I f y o u ta k e a n 8 -m in shower, how m any
g a llo n s o f w a t e r w i l l y o u save?- W h ic h w o u ld y o u u s e t o r e p r e s e n t w a t e r s a v e d e a c h m in u t e ,
a n e x p r e s s io n in v o lv in g a d d i t i o n o r a n e x p r e s s io n i n v o lv in g
subtraction? - H ow can you use the D istributive Property to fin d the total am ount
of water saved?
- W h ic h w o u ld y o u u s e t o r e p r e s e n t w a t e r s a v e d e a c h m in u t e ,
Simplify each expression.
- 6 yz + 2 yz - 8 yz
- -9m3n + 4m3n + 5mn
- 12xzy - 8 x 2 y 2 + 11 xzy - 4xdyz -.3,,2 9xy
76. - 2ab + ab + 9ab - 3ab
78. 3(—4cd - 5)
80. a — | + | a - Reasoning The D istrib u tive P roperty also applies to division, as show n.
a + b_a ,b
c ~ c + c
U s e th e D is t r ib u t iv e P r o p e r t y o f D iv is io n t o r e w r it e 9 +312”. Then sim plify. - Lawn Game Y o u p la y a g a m e w h e r e y o u t h r o w a p a i r o f
c o n n e c te d b a lls a t a s tr u c tu r e , as s h o w n a t th e r ig h t. W h e n a
p a ir w r a p s a r o u n d a b a r, y o u e a r n th e p o in t s s h o w n. Y o u to ss
3 p a irs , a n d a ll o f t h e m w r a p a r o u n d a b a r. W h ic h e x p re s s io n
c o u ld r e p r e s e n t y o u r t o t a l s c o re i f a p a ir s o f b a lls w r a p
around the blue bar?
C£> 30 + 10a C<D 10a + 20(3 - a)
GD 20 a + 3 - 10 a CED 30a + 10
I liTiW E I/U K M «)km S T iM I 1 Lesson 1-7 The Dist ribut ive Propert y 51