Solve for x in this triangle

x = 5.006 (approximate answer)

Step-by-step explanation:

According to the instructions, the two triangles are similar.  Thus, we can write and solve an equation of ratios:

 2x - 10           39

=

      78             169

                             x - 5             1

This reduces to =

                                1             169

or (after cross-multiplication)   169x - 845 = 1

Solve for x:  Add 845 to both sides, which results in 169x = 846

Dividing both sides by 169 results in x = 5.006 (approximate answer)

  answer:

  write 548 as 500 + 40 + 8. multiply each addend by 5. then add the three products to get 2,740.