Answer:
Luis’s, because he flipped the inequality sign when he subtracted
Step-by-step explanation:
Given:
7.2b + 6.5 > 4.8b – 8.1.
Amelia started by subtracting 7.2b from both sides to get 6.5 > –2.4b – 8.1.
Amelia:
7.2b + 6.5 - 7.2b > 4.8b – 8.1 - 7.2b
6.5 > -2.4b - 8.1
Correct
Luis started by subtracting 4.8b from both sides to get 2.4b + 6.5 < – 8.1.
7.2b + 6.5 - 4.8b > 4.8b – 8.1 - 4.8b
2.4b + 6.5 > -8.1
Incorrect
Shauna started by subtracting 6.5 from both sides to get 7.2b > 4.8b – 14.6
7.2b + 6.5 - 6.5 > 4.8b – 8.1 - 6.5
7.2b > 4.8b - 14.6
Correct
Clarence started by adding 8.1 to both sides to get 7.2b + 14.6 > 4.8b.
7.2b + 6.5 + 8.1 > 4.8b – 8.1 + 8.1
7.2b + 14.6 > 4.8b
Correct
Answer:
10.4 miles
Step-by-step explanation:
Write an equation for the total cost paid as a function of the # of miles driven:
L(x) = $6.75 + ($3.20/mile)x
and set this equal to $40.03 to determine the # of miles Lupita rode:
L(x) = $6.75 + ($3.20/mile)x = $40.03
Isolate the x term by subtracting $6.75 from both sides:
($3.20/mile)x = $40.03 - $6.75 = $33.28
Finally, divide both sides by ($3.20/mile):
x = $33.28 / ($3.20/mile)
= 10.4 miles
Lupita rode 10.4 miles in the taxi.
The answer is A) <span>Increasing: x < 7; decreasing: x > 7</span>
