To answer number 3 all you have to do is put 15 times x <_ 12 (put a line directly underneath the sign)
To answer number 19, do 21-11= 10 This means that X=10
X(10) plus 11=21
21=21
[10 + 11] >_ 21
To solve 16.
Add 3 to 13 to get 16
Then you’ll have [3x +4] >_ 16
Once you have this, subtract 4 from both sides.
Then you’ll have 3x>_ 12
Now you can divide each side by 3 to get x>_4. X=4
So if we plug that in [3x +4] >_ 13, you’ll get
[3(4) +4] >_ 13
And then you’ll get
[16] >_ 13
I hope this helps!!