<PRE><B>Question 315202</B>
Write an equation for each statement
:
Three numbers add up to 60.
x + y + z = 60
:
The first number is 1/3 of the second number.
x = {{{1/3}}}y
:
 The third number is twice the second number. 
z = 2y
:
What are the three numbers?
x + y + z = 60
replace x and z
{{{1/3}}}y + y + 2y = 60
:
{{{1/3}}}y + 3y = 60
Multiply eq by 3, results
y + 3(3y) + 3(60)
:
y + 9y = 180
y = {{{180/10}}}
y = 18
then
z = 2(18)
z = 36
and 
x = {{{1/3}}}*18
x = 6
:
:
Check by finding the sum of these three numbers
6 + 18 + 36 = 60
</PRE>