Question

Q. If A is a square matrix of order 2 then find the value of|A|+|-A|.________❤answer plz don't unneccessary answer plz....l will give you mark as brainliest✌☺​

Answer 1

Answer:

Step-by-step explanation:

If the elements are a,b,c and d

Then

|A|+|-A| = ad-bc+ad-bc= 2(ad - bc)

Answer 2

The value of |A|+|-A|  is 2(ad-bc)

Step-by-step explanation:

• Let A be the square matrix of order 2
• Let A=$\left[\begin{array}{cc}a&b\\c&b\end{array}\right]$

To find the value of |A|+|-A|:

First find the values of |A| and |-A|:

• |A|=$\left|\begin{array}{cc}a&b\\c&b\end{array}\right|$

|A|=a(d)-b(d)

|A|=ad-bc

• |-A|=|A|              [ by using the  property |x|=|-x| ]

|-A|=ad-bc ( since |A|=ad-bc )

Now substitute the values of |A| and |-A| in |A|+|-A| we get

• |A|+|-A|=ad-bc+ad-bc
• =2ad-2bc ( adding the like terms )
• =2(ad-bc) ( by taking the common term 2 outside the factor )
• Therefore |A|+|-A|=2(ad-bc)

Therefore the value of |A|+|-A|=2(ad-bc)