How do I solve for x correctly?

Answer:
x = 3
Step-by-step explanation:
[tex] \triangle TFG\sim \triangle TUV... (given) [/tex]
[tex] \therefore \frac{FG}{UV}=\frac{TG}{TV} ... (csst) [/tex]
[tex] \therefore \frac{45}{63}=\frac{10x+5}{49} [/tex]
[tex] \therefore \frac{5}{7}=\frac{10x+5}{49} [/tex]
[tex] \therefore 10x+5= \frac{5\times 49}{7} [/tex]
[tex] \therefore 10x+5=5\times 7 [/tex]
[tex] \therefore 10x+5=35 [/tex]
[tex] \therefore 10x=35-5 [/tex]
[tex] \therefore 10x=30 [/tex]
[tex] \therefore x=\frac{30}{10} [/tex]
[tex] \therefore x=3[/tex]