Fir this simple problem you need to create an equation , because of the word "equal" meaning equals to.
Less mean subtraction.
X - 3 = 13 I am guessing here that you want to find X=? if this is not the case and you trying to write and algebra expression , that is your answer; X-3 +13
If you need to find X.
X - 3 =13. adding +3 in both sides of the equation i got:
X= 16 Answer.
Note: if yu need to check your answer , plug x=3 back in the original equation that you created.
X - 3 = 13
16 -3 =13
13=13. check √