Recall that variables represent changing values. In this unit, you will work with equations that contain two different variables. What types of situations might be modeled with equations containing two or more variables? If the value of one variable changes, must
the value of the other variable change for the equation to remain true? How would the
number of solutions for an equation with two variables differ from the number of solutions for an equation with only one? Explain.

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.