What is an equation with more than one variable called a. a literal equation
b. a variable
c. an expression
d. a quadratic equation

option A

a variable is a number which is always changing

an  expression doesn't have an equal sign

a quadratic equation is an equation which has one variable but the highest power of that variable is 2

so the answer is a literal equation or linear equation in two variables

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.