Answer
False. A true statement is:
"a matrix row operation such as $\frac{-4}{5}{{R}_{1}}+{{R}_{2}}$ is permitted".
Work Step by Step
A matrix row operation can be performed by multiplying any row by a non-zero real number and adding one row to another row.
Since ${{R}_{1}}$ is multiplied by $\frac{-4}{5}$ which is a real number and ${{R}_{2}}$ is added to $\frac{-4}{5}{{R}_{1}}$ the values obtained are real numbers.
Therefore, the provided operation is permitted.
So, the given statement is false.
Hence, the provided statement is false and the true statement is:
a matrix row operation such as $\frac{-4}{5}{{R}_{1}}+{{R}_{2}}$ is permitted.