You only get to ask two questions.  So the others were deleted:
1. What is the formula for the determinant of a 3 x 3 matrix ?
 
 = aei + bfg + cdh - ceg - bdi - afh
 = aei + bfg + cdh - ceg - bdi - afh 
2. Solve the inequality |2x − 4| < 10. Write the solution in interval notation and graph it:
To remove absolute value bars with < or <, write
                              -10 < 2x - 4 < 10, and solve for x in the middle:
Add 4 to all three sides       +4       +4   +4                           
                              ------------------
                               -6 < 2x     < 14
Divide all three sides by 2    -3 <  x     <  7
Here is the graph:
                    -----------o=============================o------------
                    -6  -5 -4 -3 -2 -1  0  1  2  3  4  5  6  7  8  9 10 11
Here is the interval notation, which is an abbreviation for the graph:
                                     (-3,7)
     
Edwin