Let x and y represent the numbers of gallons used by the 40 mpg and 35 mpg cars, respectively.
.. x +y = 40 . . . . . . . . . . .total consumption is 40 gallons
.. 40x +35y = 1525 . . . . total miles driven = 1525
Multiply the first equation by 40 and subtract the second.
.. 40(x +y) -(40x +35y) = 40(40) -(1525)
.. 5y = 75
.. y = 15
.. x = 40 -15 = 25
The 40 mpg car consumed 25 gallons.
The 35 mpg car consumed 15 gallons.
Answer:
Hey again! Just remember about the number lines. If it's easier, you can use a calculator to divide the fractions to make them easier to visualize in decimal form.
The answer to this one is:
-2.4
-2.25
-11/5 (which is -2.2)
-15/10 (1.5)
-1.6
B.)10 inches
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you need to plug in 10
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thats if you don't know what to do
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the easy way
compound interest equation for annually compounded
A=final amount
P=principal
r=rate in decimal
t=time in years
given that
A=1550
P=1000
r=5.5%=0.055
find t
divide both sides by 1000
take ln of both sides
use ln rule 
divide both sides by ln(1.055)
using a calculator, we get that t=8.18544 yrs
so about 8.2yrs
