After 2.0 years, the 4.0 mg sample decays to 2.0 mg.
After another 2.0 years (total 4.0 years), the 2.0 mg sample decays to 1.0 mg.
And after another 2.0 years (total 6.0 years), the 1.0 mg sample decays to 0.50 mg.
So it takes 6.0 years for 4.0 mg to decay to 0.50 mg.
Answer:
-55 and -53
Step-by-step explanation:
The equation would be 4y=5x 4(x+15)=5x x+15=y
let x be the amount that Shelia deposits each time
let y represent the amount that Sherri deposits each time
4(x+15)=5x
4x+60=5x
-4x -4x
60=x
Check:
x+15=y 60+15=y y=75
4(75)=5(60)
300=300
Shelia deposits $60 each time.
Answer:
106
Step-by-step explanation:
divided 320 by 3