A boy has 5-dollar coins and a 10-dollar coins. They are eight coins all together and their value is 55 dollars. How many of each kind does he have?
+73 let's define some variables: x and y, for the 5-dollar coins and the 10-dollar coins, respectively.
now let's create a system of equations -
x + y = 8
5x + 10y = 55.
we can simplify that second equation by dividing both sides by 5. now we get:
x + y = 8
x + 2y = 11
let's use elimination and subtract these two equations.
subtracting, we get y = 3.
now to solve for the amount of 5-dollar coins there are, we can plug in our value of y in one of the equations.
x + 3 = 8
x = 8 - 3
x = 5.
hope this helped! please let me know if you are confused about anything i did :)
