Respuesta :
Answer: 13 minutes
================================================
Explanation:
x = time it takes for the bell to ring, time is in minutes
d = distance from his house to the school, in meters
distance = rate*time
If Andrew walks at a speed of 50 meters per minute, then he'll be 3 minutes late. This means he took x+3 minutes to get to class. The x represents the amount of time it takes if he arrived on time, then the +3 is those 3 minutes he is late. We then write
d = 50(x+3)
d = 50x+150
If he runs to school, then he's 3 minutes early. So he took (x-3) minutes to get to class. His rate is 80 meters per minute
d = 80(x-3)
d = 80x-240
We're referring to the same distance (d) value, which allows us to perform substitution to solve the two equations we formed
80x-240 = 50x+150
80x-50x = 150+240
30x = 390
x = 390/30
x = 13
Andrew has 13 minutes to get to class.
-------------------
Checking the answer:
If he walks at a speed of 50 m per minute, then he'll be 3 minutes late. So he really took 13+3 = 16 minutes to arrive. His distance traveled is d = r*t = 50*16 = 800 meters.
If he ran 80 m per minute, and is 3 minutes early, then he took 13-3 = 10 minutes to get to class. His distance is the same as before d = r*t = 80*10 = 800 meters. The fact we get 800 both times helps confirm we have the right answer.
Andrew has 13 minutes to get to class.
What is Algebra?
Algebra is the part of mathematics that helps represent problems or situations in the form of mathematical expressions.
In algebra, we use numbers like 2, −7, 0.068 etc., which have a definite or fixed value. In algebra we use variables like x, y, and z along with numbers.
Now, let x be the time it takes for the bell to ring.
let d be the distance from his house to the school, in meters
distance = speed*time
If Andrew walks at a speed of 50 meters per minute, then he'll be 3 minutes late.
So, Andrew took x+3 minutes to get to class.
Here in the expression +3 shows that she is late.
So,
d = 50(x+3)
d = 50x+150
Now, If he runs to school, then he reached 3 minutes early.
So, toe get in class he will take (x-3) minutes
Here -3 show the child reached early
d = 80(x-3)
d = 80x-240
Since the distance is same.
So, the two equations are equal.
80x-240 = 50x+150
80x-50x = 150+240
30x = 390
x = 390/30
x = 13
Hence, Andrew has 13 minutes to get to class.
Learn more about algebra here:
https://brainly.com/question/953809
#SPJ2