
??
9 + 1 × 9 + 1
Do the multiplication first.
1 × 9 = 9
Now put it back:
9 + 9 + 1
9 + 9 = 18
18 + 1 = 19
So the answer is 19.

??
9 + 1 × 9 + 1
Do the multiplication first.
1 × 9 = 9
Now put it back:
9 + 9 + 1
9 + 9 = 18
18 + 1 = 19
So the answer is 19.