A café sells a regular cup of coffee for $1 and a large cup for $1.50. Melissa and her friends buy 5
cups of coffee and spend a total of $6. Explain how
to write and solve a system of equations to find the
number of large cups of coffee they bought.

if x is a regular cip of coffee and y is a large cup of coffee. the first part of the equation being the number of the cups of coffee and the second part expressing the price. using the method of substitution we solve for x in the first equation

x= 5-y

and then we solve for y

then we substitute the value found in the easiest equation which would be the first one and we solve for x

x + 2 = 5

x + 2 - 2 = 5 - 2

x = 3

so its 3 regular cups and 2 large

or