Exercise · ZW-MATRIX-004 · ★☆☆ Basic
Compute \(3A\) if \(A=\begin{pmatrix}1&-2\\0&4\end{pmatrix}\).
Choose one option.
Show answer
- B. \(\left[\begin{matrix}3 & -6\\0 & 12\end{matrix}\right]\)
Explanation
Multiplying a matrix by a scalar multiplies every entry by that scalar: \(3A=\begin{pmatrix}3&-6\\0&12\end{pmatrix}\).
Review the concept: Matrix
A matrix \(A\) is a rectangular array of numbers arranged in rows and columns; with \(m\) rows and \(n\) columns, it has size \(m\times n\).
\[A=\begin{pmatrix}a_{11}&\cdots&a_{1n}\\ \vdots&\ddots&\vdots\\ a_{m1}&\cdots&a_{mn}\end{pmatrix}\]
More practice problems: matrix
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