Respuesta :
Answer:
90
Step-by-step explanation:
9x10 is nine ten times or ten nine times
9+9+9+9+9+9+9+9+9+9=90
or
10+10+10+10+10+10+10+10+10=90
An easy trick for doing anything muliplied by 10 is to just add an extra 0 on the end of the first number!