Answer: x = 5
Step-by-step explanation:
If two angles are similar then the ratio of their sides are equal, that is
[tex]\frac{4x}{3x+1} = \frac{15}{12}[/tex]
cross multiplying , we have
[tex]4x ( 12 ) = 15 ( 3x + 1 )[/tex]
[tex]48x =[/tex] [tex]45x + 15[/tex]
[tex]48x - 45x = 15[/tex]
[tex]3x = 15[/tex]
[tex]x = 5[/tex]
