Answer:
x = 3 which means he has 3 nickels
y = 7 which means he has 7 dimes
Step-by-step explanation:
5x + 10y = 85
x + y = 10
-5 (x + y = 10) Multiply equation by -5 to delete the x's
-5x -5y = -50
5x + 10y = 85 Subtract the new equation from the 2nd equation
5y = 35
y = 7
x + 7 = 10
x = 3
x = 3 which means he has 3 nickels
y = 7 which means he has 7 dimes
Answer:
Step-by-step explanation:
Before getting to solve the two equations: x+y=10 and 5x+10y=85, we look at how we get them.
Let the number of nickels be x, and the number of dimes be y.
Manny has 85 cents in nickels and dimes. Nickels are 5-cent each and dimes are 10-cent each. So 5x+10y=85.
He has 10 coins altogether. So x+y=10
Now rearranging, y=10-x
Substituting that into the other equation
5x+10(10-x)=85
5x+100-10x=85
10x-5x=100-85
5x=15
x=3
y=10-3=7
