Practice Problems Math 7+ U7 Day 5 (L9 & 10)

Cell phone Plan A costs $70 per month and comes with a free $500 phone. Cell phone Plan B costs $50 per month but does not come with a phone.What is the equation for Plan A if y = total cost and x = # of months?

• y = 70x

• y = 70 + x

• y = 70x + 500

• y = 70x - 500

Cell phone Plan A costs $70 per month and comes with a free $500 phone. Cell phone Plan B costs $50 per month but does not come with a phone.What is the equation for Plan B if they but the $500 phone and y = total cost and x = # of months?

• y = 50x

• y = 50 + x

• y = 50x + 500

• y = 50x - 500

Cell phone Plan A costs $70 per month and comes with a free $500 phone. Cell phone Plan B costs $50 per month but does not come with a phone. You buy the $500 phone and choose Plan B. How will you determine how many months is it until your cost is the same as Plan A's?

• add the equations together

• set the equations equal to zero

• set the equations equal to each other

• subtract the equations

Cell phone Plan A costs $70 per month and comes with a free $500 phone. Cell phone Plan B costs $50 per month but does not come with a phone. If you buy the $500 phone and choose Plan B, how many months is it until your cost is the same as Plan A's?

• 20 months

• 25 months

• no solution

• 10 months

Priya and Han are biking in the same direction on the same path. Han is riding at a constant speed of 16 miles per hour. Write an expression that shows how many miles Han has gone after t hours.

• 16

• 16x

• 16t

• 16+t

Priya and Han are biking in the same direction on the same path. Priya started riding a half hour before Han. If Han has been riding for t hours, how long has Priya been riding?

• 2t

• t + 1/2

• t - 1/2

• 1/2 t

Priya is riding at a constant speed of 12 miles per hour. Write an expression that shows how many miles Priya has gone after Han has been riding for t hours.

• 12t

• 12(1/2)

• 12(t - 1/2)

• 12(t + 1/2)

Using the expressions: for Han use 16t and for Priya use 12(t+1/2) how would you find when Han and Priya meet?

• Set the expression equal to each other

• Set the expression equal to zero

• Add the expressions

• Subtract the expressions

When do they meet - in how many hours?

• 3 hours

• 3/2 hours or 1 1/2 hours

• 2 hours

• 6 hours

Which story matches the equation − 6 + 3x x = 2 + 4 ?

• At 5 p.m., the temperatures recorded at two weather stations in Antarctica are -6 degrees and 2 degrees. The temperature changes at the same constant rate, x degrees per hour, throughout the night at both locations. The temperature at the first station 3 hours after this recording is the same as the temperature at the second station 4 hours after this recording

• Elena and Kiran play a card game. Every time they collect a pair of matching cards, they earn points. At one point in the game, Kiran has -6 points and x Elena has 2 points. After Elena collects 3 pairs and Kiran collects 4 pairs, they have the same number of points.