 |
| Some properties of Addition and Subtraction of Matrices |
|
| (1) A + B = B + A (Commutative property) |
| |
| (2) k(A + B) = kA + kB (Distributive property) |
| |
| (3) (A + B) + C = A + B + C (Distributive property) |
| |
| (4) (A + B) + C = A + (B + C) (Associative property) |
| |
| A + O = O + A = A where O is zero or null matrix. |
| |
 A = A + O |
| |
| (5) A + (-A) = O (-A is additive inverse of A) |
| |
| Zero matrix possesses identity property of addition. |
| |
| (6) If A + B = C then B = C - A |
| |
 |
| |
If  , then find 2A + 3B - 4C. |
| |
 |
| |
2A + 3B - 4C =  |
| |
 |
| |
 |
| |
 |
| |
If  , find a, b, c. |
| |
|
|
| |
 |
| |
 |
| |
 3a = 21  a = 7 |
| |
 2b = 8  b = 4 |
| |
 7c = -28  c = -4. |
| |
| Ans: a = 7, b = 4, c = -4. |
| |
