The jar only contains nickels and dimes altogether there are 10 coins total of the value is 90 cents how many nickels and how many dimes are there in the jar

Write a system of equations and solve.

x + y = 10
5x + 10y = 90

Multiply and combine equations

-5x - 5y = -50
5x + 10y = 90

5y = 40
y = 8
x = 2

There are 2 nickels and 8 dimes in the jar. Hope this helps! :)

A: 18/15b : 7 - -8 = 15 , 12 - -6 = 18 the y variable always goes over the x variables, c : same thing a