A linear equation only has one or two variables. No variable in a linear equation is raised to a power greater than 1 or used as the denominator of a fraction. When you find pairs of values that make a linear equation true and plot those pairs on a coordinate grid, all of the points lie on the same line
Let the number of nickels and quarters be x.
Value of nickel = 5 cents = $0.05
Value of quarters = 25 cents = $0.25
Thus, the total value equals
0.05x +$1.80 = 0.25x
$1.80 = 0.25x - 0.05x
$1.80 = 0.2x
x = 1.80/0.2
x = 9 coins
Thus the total value of all coins together is ($0.05+$0.25)x 9 = $0.3 x 9
