Answer:
Perimeter of Triangle: [tex]6x+15[/tex]
[tex]x=12.5[/tex]
Step-by-step explanation:
The perimeter is the sum of all of the sides of the triangle.
Hence, the perimeter [tex]=3x+3x+15=6x+15[/tex]
Since the perimeter is 90, [tex]6x+15=90[/tex].
Subtract 15 from both sides:
[tex]6x+15-15=90-15[/tex]
[tex]6x=75[/tex]
Divide both sides by 6:
[tex]\frac{6x}{6}=\frac{75}{6}[/tex]
[tex]x=12.5[/tex]
