Question

In a triangle ABC, AB:BC is 5:9. On the triangle AB=15 and BC=5x+2. Write a proportion and solve for the variable

Answer 1

If AB is 15, then BC is 15*9/5=27.  Therefore, we can write the equation 5x+2=27.

We subtract by 2 to find that 5x=25, and divide by 5 to see that x=5.