Answer :
Assuming that "l" and "m" are parallel, we solve this by corresponding angles.
The term corresponding angles is often used when two lines are cut by a third line, a transversal. The corresponding angles postulate states that if "l" and "m" are parallel, then the pairs of corresponding angles are congruent.
Therefore we can do the following equality:
[tex]4x+7=6x-63[/tex]Now, we solve to "x"
[tex]\begin{gathered} 6x-4x=4+63 \\ 10x=70 \\ x=\frac{70}{2} \\ x=35 \end{gathered}[/tex]In conclusion, the answer is:
[tex]x=35[/tex]