CH 2.3 Formulas and Problem Solving

Multiple Choice

Solve for y: $$4y-5x=9$$  .

• $$y=\frac{5}{4}x+\frac{9}{4}$$  

• $$x=\frac{4}{5}y-\frac{9}{5}$$  

• $$y=-\frac{5}{4}x+\frac{9}{4}$$  

• $$y=-5x+\frac{9}{4}$$  

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Multiple Choice

The fastest average speed by a cyclist across the continental United States is 15.4 mph, by Pete Penseyres. If he traveled a total distance of about 3107.5 miles at this speed, find his time cycling.

What formula would be used to find his time?

• $$A=lw$$  

• $$I=PRT$$  

• $$P=a+b+c$$  

• $$d=rt$$  

Multiple Choice

The fastest average speed by a cyclist across the continental United States is 15.4 mph, by Pete Penseyres. If he traveled a total distance of about 3107.5 miles at this speed, find his time cycling.

Substitute the variables in the formula $$d=rt$$ with the appropriate values.

• $$3107.5=15.4t$$  

•   $$3107.5=r\left(15.4\right)$$  

•   $$15.4=3107.5t$$  

•   $$d=3107.5\left(15.4\right)$$  

​201.7857143 hours