I am not positive for the factoring of each expression but for the distributive property you do 8 TIMES x then 8 times 7 so you would get blank plus blank and so on for the next ones.
3x-5=19-x
3x-5-19+x=0
4x-24=0
4x=24
x=6
(a) True. Suppose A is a not a square matrix, with m rows and n columns. Then A² is not defined, because you can't multiply an m×n matrix by another m×n matrix.
(b) False. As an example, consider the matrices


Then both AB and BA are defined, with


In general, you can multiply any m×n by any n×m matrix.
(c) True. Multiplying a m×n matrix by a n×m matrix always yields a m×m matrix, and multiplying a n×m matrix by a m×n matrix always yields a n×n matrix.
It would be C:55,
hope this helps u out