Answer:
b11 = -14
b12 = 9
b13 = 8
Step-by-step explanation:
* Lets revise some notes to solve the problem
- Any matrix has a dimension m × n, where m is the number of rows
and n the number of columns
- We can add matrices with same dimensions
* Now lets solve the problem
∵ [tex]B+\left[\begin{array}{ccc}15&-7&4\\0&1&2\end{array}\right]=\left[\begin{array}{ccc}1&2&12\\4&0&2\end{array}\right][/tex]
- Let [tex]B=\left[\begin{array}{ccc}b11&b12&b13\\b21&b22&b23\end{array}\right][/tex]
∴ [tex]\left[\begin{array}{ccc}b11&b12&b13\\b21&b22&b23\end{array}\right]+\left[\begin{array}{ccc}15&-7&4\\0&1&2\end{array}\right]=\left[\begin{array}{ccc}1&2&12\\4&0&2\end{array}\right][/tex]
- Lets add and find the missing
* Lets start with the first rows
∵ b11 + 15 = 1 ⇒ subtract 15 from both sides
∴ b11 = -14
∵ b12 + -7 = 2 ⇒ add 7 to both sides
∴ b12 = 9
∵ b13 + 4 = 12 ⇒ subtract 4 from both sides
∴ b13 = 8
* Now lets start with the second rows
∵ b21 + 0 = 4
∴ b21 = 4 ⇒ given
∵ b22 + 1 = 0 ⇒ subtract 1 from both sides
∴ b22 = -1 ⇒ given
∵ b23 + 2 = 2 ⇒ subtract 2 from both sides
∴ b23 = 0 ⇒ given
