Question

lesson 9 practice problems
1 a car has a 16 - gallon fuel tank. when driven on a highway, it has a gas mileage (also called fuel efficiency) that tells us the number of miles it can travel for a particular amount of fuel (one gallon of gasoline, in this case). after filling the gas tank, the driver got on a highway and drove for a while.
a. how many miles has the car traveled if it has the following amounts of gas left in the tank?
i. 15 gallons
32 miles
ii. 10 gallons
iii. 2.5 gallons
b. write an equation that represents the relationship between the distance the car has traveled in miles, d, and the amount of gas left in the tank in gallons, x.
( d = 480 - 30x )
c. how many gallons are left in the tank when the car has traveled the following distances on the highway?
i. 90 miles
13 gallons 7.8 gallons
ii. 246 miles
d. write an equation that makes it easier to find the the amount of gas left in the tank, x, if we know the car has traveled d miles.
2 the area a of a rectangle is represented by the formula ( a = lw ) where l is the length and u is the width. the length of the rectangle is 5.
write an equation that makes it easy to find the width of the rectangle if we know the area and the length.

Explanation:

Step1: Rearrange the formula

Given \(A = lw\), we want to solve for \(w\). Divide both sides of the equation by \(l\).
\(A\div l=(lw)\div l\)

Step2: Simplify the equation

Since \((lw)\div l = w\) (when \(l
eq0\)), the simplified equation is \(w=\frac{A}{l}\).

Answer:

\(w=\frac{A}{l}\)