His work should have looked like this.
2x + y = 5
x − 2y = 10
y = 5 − 2x
x − 2(5 − 2x) = 10
x − 10 + 4x = 10
5x − 10 = 10 When he added in both sides, he subtracted 10 from 10,
5x = 20 instead of adding 10 from 10 to make 20.
x = 4
2(4) + y = 5
8 + y = 5
y = -3
M = 1 - 2 / 3 - 1
m = - 1 / 2
Answer:
he got 40
Step-by-step explanation:
10/0.25
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
60 seconds x 60 minutes = 3,600 seconds per hour
3,600 seconds per hour x 24 hours = 86,400 seconds per day.
The light flashes 5 times every 10 seconds:
5 flashes / 10 seconds = 1 flash every 2 seconds
86,400 seconds / 2 seconds = 43,200 flashes per day.
