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put this solution on YOUR website!3. In captivity, the average life span of a grizzly bear is 9 years more than that of a tiger. The sum of the two average life spans is 41 years. Find the average life span of a tiger in captivity.
a. Define the variables.
Let t be tiger's life span and b be the bear's life span.
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b. Write the expression for the life span of a grizzly bear in terms of the life span of a tiger. g=t+9
c. Write an equation for the sum of their life spans in term of one variable.
t+t+9 = 41
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d. Solve the equation for the life span of a tiger.
2t = 32
t=16
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4. George is 12 years older than Jeannie. The sum of their ages in 5 years will be 50. How old is Jeannie now?
a. Define the variables.
George's age is g ; Jeannie's age if j.
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b. Write an expression for the age of George in terms of Jeannie's age.
g = j-12
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c. Write an equation for the sum of their ages in 5 years from now.
g+5 + j+5 = 50
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d. Solve the equation for the age of Jeannie now.
(j-12)+5 + j+5 = 50
2j - 2 = 50
2j = 52
j = 26 yrs old
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5. Mandy begins bicycling west at 20mph. Liz leaves from the same point 1 hour later bicycling west at 30mph. When will she catch up with Mandy?
a. Define the variables
Mandy's time is t; Liz's time is t-1.
b. Make a chart.
distance=rate x time Rate Time Distance
Mandy: rate = 20 mph ; time = t ; distance= 20t
Liz..: rate = 30 mph ; time = t -1 ; distance = 30(t-1)
c. Set the distances equal to one another (they travel the same distance) and solve the equation for t.
20t = 30(t-1)
20t = 30t-30
10t = 30
t = 3 hrs
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d. What does t represent?
Mandy's time.
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Cheers,
Stan H.
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