<PRE><B>Question 540215</B>

Write an equation for each statement
;
Five times a number minus twice another number equals twenty-two.
 5x - 2y = 22
:
The sum of the numbers is three.
x + y = 3
y = (3-x); use this form for substitution
:
Substitute (3-x) for y in the 1st equation
5x - 2(3-x) = 22
5x - 6 + 2x = 22; you have to change the sign of -x when you mult it by -2
5x + 2x = 22 + 6
7x = 28
x = 28/7
x = 4
find y
y = 3 - 4
y = -1
:
Our solution, x=4, y =-1
:
Check these solutions in the 1st statement:
Five times a number minus twice another number equals twenty-two.
5(4) - 2(-1) = 
20 + 2 = 22; confirms our solutions</PRE>