STEP 1:
x= one number
2x-3= other number
x + (2x-3)= -12
combine like terms
3x - 3= -12
add 3 to both sides
3x= -9
divide both sides by 3
x= -3 one number
STEP 2:
substitute x= -3 to find other number
2x-3= 2(-3)-3= -6-3= -9 other number
CHECK:
-3 -9= -12
-12= -12
ANSWER: One #= -3, Other #= -9
Hope this helps! :)
