Hey there!
ORIGINAL PROBLEM/EQUATION:
x + x - x = 15
CONVERSION/NEW EQUATION:
1x + 1x - 1x = 15
COMBINE the LIKE TERMS:
2x - 1x = 15
1x = 15
DIVIDE 1 to BOTH SIDES
1x/1 = 15/1
SIMPLIFY AFTER CANCELING OUT 1/1 BECAUSE IT GAVE YOU 1 & KEEPING 15/1 BECAUSE IT HELP/GIVE YOU THE x-value
NEW EQUATION: x = 15
Therefore, your answer is: x = 15
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)