Answer:
Fill it with number but do it on paper
Step-by-step explanation:
You have to subtract to get the inverse operation
The element 
is the entry in the 1st row and 3rd column of the matrix, which, in this case, is 7.
Edit: Got my rows/columns mixed up! Row 1, Column 3 is actually -1, as the original poster pointed out.
Answer:
option A
Step-by-step explanation:
<h2><em>Note: </em></h2>
when there is an open circle, that means Less than or equal to.
if and when there is a Closed, colored Circle, It's Greater than or equal to or less than or equal to
Answer: a<13
Step-by-step explanation:
a*(a+1)<a^2+13
a^2+a<a^2+13
subtract a^2 from both sides:
a<13
