SOLUTION: Eric has some quarters, x, and nickels, y in his pocket. He has 8 more nickels than quarters. The total value is $1.00. Write two equations that could be used to solve the system.

Algebra ->  Customizable Word Problem Solvers  -> Coins -> SOLUTION: Eric has some quarters, x, and nickels, y in his pocket. He has 8 more nickels than quarters. The total value is $1.00. Write two equations that could be used to solve the system.       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 987844: Eric has some quarters, x, and nickels, y in his pocket. He has 8 more nickels than quarters. The total value is $1.00. Write two equations that could be used to solve the system. Solve for Y and Graph.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Eric has some quarters, x, and nickels, y in his pocket.
He has 8 more nickels than quarters.
The total value is $1.00.
Write two equations that could be used to solve the system. Solve for Y and Graph.
:
equations for the given statements
:
"He has 8 more nickels than quarters."
y = x + 8; graph red line
:
" The total value is $1.00."
.25x + .05y = 1.00
multiply by 100 to get rid of the decimals
25x + 5y = 100
convert to slope intercept form, to solve for y
5y = -25x + 100
Divide eq by 5
y = -5x + 20, graph green line
:
solve the system of equations, replace y with (x+8) in the 2nd equaton
x + 8 = -5x + 20
x + 5x = 20 - 8
6x = 12
x = 12/6
x = 2 quarters
then
y = 2 + 8
y = 10 nickels
:
Graph these two equations,
+graph%28+300%2C+200%2C+-5%2C+10%2C+-10%2C+20%2C+x%2B8%2C+-5x+%2B+20%29+
note that it intersects at x=2; y=10, our solution