Answer: See explanation
Step-by-step explanation:
a. Marisa drives 112 miles in 1 hour and 45 minutes, which means her speed is 64 miles per hour.
Speed = Distance / Time
= 112 / 1 45/60
= 112 / 1 3/4
= 112 × 4/7
= 64 miles per hour.
TRUE
b . If 6 pens cost $7.74, then 7 pens cost $9.03.
Cost of one pen = $7.74/6 = $1.29
Cost of 7 pens = $1.29 × 7 = $9.03
TRUE
c. If Raymond drives at a speed of 57 miles per hour, then it takes him 4 hours and 10 minutes to drive 256.5 miles.
Speed = Distance / Time
Speed = 256.5 / 57 = 4.5 = 4 hours 30 minutes
FALSE
d. If 17 identical cans of soup cost $38.59, then 3 of the cans must cost $6.81.
Cost of one can = $38.59 / 17 = $2.27
Cost of 3 cans = $2.27 × 3 = $6.81
TRUE
e. Mr. Mayes buys two dozen eggs for $8.40, which means that he pays 70 cents per egg.
A dozen = 12
2 dozens = 12 × 2 = 24
Cost of one egg = $8.40 / 24 = 0.35 = 35 cents
FALSE
Answer: x = 5
Step-by-step explanation:
1. Set the two given expressions equal to each other (because the problem says they are interchangeable)
-5x = -40+3x
2. Subtract 3x from -5x to have x on one side of the equation.
-8x = -40
3. Divide each side by -8 to get the value of x.
x = 5
The answer is -5, -5 added by 5 cancels each other out. Then when you add 4x + 8x, you get 12x. So when you do 12x= -60, you get -5.
