Matthew and Mark were selling cups of lemonade. Matthew sold 15 more cups of lemonade than Mark. Together they sold 81 cups. How many cups did Matthew sell?

48 cups

Step-by-step explanation:

Matthew and Mark were selling cups of lemonade.

Let the number of cups that Matthew sold = x

The number of cups Mark sold = y

Together they sold 81 cups.

= x + y = 81 cups Equation 1

Matthew sold 15 more cups of lemonade than Mark.

x = y + 15 cups

Substituting y + 15 for x in Equation 1

y + 15 + y = 81 cups

2y +15 = 81 cups

2y = 81 -15

2y = 66 cups

y = 66 cups/2

y = 33 cups

Hence, the number of cups Mark sold = 33 cups.

The number of cups Matthew sold is calculated as:

= x = y + 15 cups

x = 33 cups + 15 cups

x = 48 cups

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.