Page 74 - Algebra 1

b. _2÷(-_3) 95
SOLUTION
_2 ÷ ( - _3 ) 95
Reading Math
Youcanwrite-_3 as-_3
3 or _-5 .
55
_2 · (-_5 ) 935
Multiply by the reciprocal of -_3 . _2 · (-_5 ) = -_10 The product of two fractions with
9 3 27 different signs is negative. Application: Cave Exploration
Example
5
The Voronya Cave in Abkhazia, Georgia is the deepest known cave in the world. At an elevation of -2140 meters, Voronya is a challenge for experienced cavers. If it takes 8 days to travel to the bottom of the cave, what is the average number of meters the cavers would travel each day?
SOLUTION
Write an expression.
elevation of cave number of days to travel
-2140 m ÷ 8 days -2140 ÷ 8 = -267.5
The cavers would travel an average of -267.5 meters per day.
Simplify each expression. Justify your answer.
(Ex 1)
a. 9(-0.8)
b. -12(-2.5)
Simplify each expression.
(Ex 2)
c. (-4)3 d. (-8)4 e. -54
Simplify each expression. Justify your answer.
(Ex 3)
f. -105 ÷ (-7) g. 63.9 ÷ (-3)
Evaluate each expression.
(Ex 4)
h. -_4 ÷⎛⎝-_9 ⎞⎠ i. _3 ÷⎛⎝-_3⎞⎠ 510 84
j. Science During a cold spell in January 1989, Homer, Alaska, recorded (Ex 5) a low temperature of −24°F. The city of Bethel, Alaska, recorded
a low temperature twice as cold as the low in Homer. What was the temperature in Bethel, Alaska?
Lesson Practice
Lesson 11 59