13. In $\triangle M N P$, if $m \angle M=(4 x-3)^{\circ}, m \angle N=(9 x-6)^{\circ}$, and $m \angle P=(6 x-1)^{\circ}$, find the value of $x$ and the measure of each angle.
\[
\begin{array}{r}
x= \\
m \angle M= \\
m \angle N= \\
m \angle P=
\end{array}
\]
14. In $\triangle R S T$, if $m \angle R$ is five more than twice $x, m \angle S$ is one more than $x$, and $m \angle T$ is sixteen less than seven times $x$, find $x$ and the measure of each angle.

Step 1 ：Given that $\triangle MNP$ is a triangle, the sum of its interior angles is 180 degrees. Therefore, we can write the equation: $(4x - 3) + (9x - 6) + (6x - 1) = 180$

Step 2 ：Combine like terms on the left side of the equation: $19x - 10 = 180$

Step 3 ：Add 10 to both sides of the equation: $19x = 190$

Step 4 ：Divide both sides of the equation by 19: $x = 10$

Step 5 ：Substitute $x = 10$ into the expressions for $m \angle M, m \angle N,$ and $m \angle P$ to find the measures of these angles: $m \angle M = 4x - 3 = 4(10) - 3 = 37$ degrees, $m \angle N = 9x - 6 = 9(10) - 6 = 84$ degrees, $m \angle P = 6x - 1 = 6(10) - 1 = 59$ degrees

Step 6 ：So, the value of $x$ is $\boxed{10}$, and the measures of the angles are $m \angle M = \boxed{37}$ degrees, $m \angle N = \boxed{84}$ degrees, and $m \angle P = \boxed{59}$ degrees