The average of the three numbers x, y and z is equal to twice the average of y and z. What is the value of x in terms of y and z?

Question

Warm up 6 math counts 2008 2009 page 30

Answer 1

The average of x, y, and z is (x + y + z)/3

 

The average of y and z is (y + z)/2

 

(x + y + z)/3 = 2(y + z)/2 = (y + z)

 

x + y + z = 3(y + z)

 

x = 3(y + z) - (y + z) = 2(y + z)