Equations
Pedro saves $15 each month. Write the equation for dollars after m months.
Answer: d=15m
Write the ratio of 4 red marbles to 6 blue.
Answer: 4:6 or 2:3.
Car A travels 240 miles on 12 gallons. What’s the mpg?
Answer: 20 mpg.
What makes a graph proportional?
Answer: Straight line through origin.
Scale factor 2: Original length 5 → new length?
Answer: 10.
Babysitter earns $12/hour. How much for 8 hours?
Answer: $96
Eve mixes ¾ red to ⅔ yellow paint. If she uses 1 oz red, how much yellow?
Answer: 8/9 oz
A pack of 6 pencils costs $3. Find cost per pencil.
Answer: $0.50 each.
Laundry pods graph shows (1,12). What does that mean?
Answer: 12 pods used per month.
Scale factor ½: Original length 12 → new length?
Answer: 6.
A taxi charges $3 per ride plus $2 per mile. Equation?
Answer: C=2m+3
A recipe calls for 2 cups sugar to 3 cups flour. How much flour for 6 cups sugar?
Answer: 9 cups flour
150 miles in 3 hours. Find speed.
Answer: 50 mph.
Equation for bike rentals: $2.50 per hour.
Answer: C=2.5t
Rectangle 8 × 2 scaled by 2.5. New area?
Answer: 108.75 sq cm
Solve: If 5x=45, what is x?
Answer: 9
Simplify ratio 24:36.
Answer: 2:3.
A 12-pack of sodas costs $4.80. Find cost per can.
Answer: $0.40 each.
Fill missing value: If x=4, y=20 on y=5x.
Answer: y = 20.
If scale factor is 3, how does area scale?
Answer: By 32=9
A gym charges $25 per month plus a one-time fee of $50. Write the equation.
Answer: C=25m+50
Water bottles to energy drinks is 5:3. How many energy drinks for 25 water bottles?
Answer: 15.
Car A uses 21 gallons for 590 miles, Car B uses 23.5 gallons for 568.7 miles. Which is more efficient?
Answer: Car A (28.1 mpg vs. 24.2 mpg).
A graph shows points (2,10), (3,15), (4,20). Write the equation.
Answer: y = 5x.
Figure A scaled by ⅗ from the original. If original side is 15, new side?
Answer: 9.