There you go and sorry if it’s not that clear:
A dime = 0.10
A nickel = 0.05
N + D = 28 coins
Rewrite this as N = 28 -D
0.10D + 0.05N = 1.95
Replace N withe the rewritten equation above:
0.10D + 0.05(28-D) = 1.95
Use the Distributive Property:
0.10D + 1.4 - 0.05D = 1.94
Add the like terms:
0.05D + 1.4 = 1.95
Subtract 1.4 from both sides:
0.05D = 0.55
Divide both sides by 0.05
D = 0.55 / 0.05
D = 11
Nickels = 28 - 11 = 17
There are 11 dimes and 17 nickels.
Answer:
3 hours
Step-by-step explanation:
Rodriguez did 1/3 of the job, so the remaining 2/3 of the job will take the assistant 2/3 of the usual time:
(2/3)(4 1/2) = 3 . . . hours
The assistant can complete the job in 3 hours.