Could someone please help me out with this

Give the equations of two different lines that are perpendicular to the line 3x + 4y = 7.

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?

What are the excluded values? m+5/mn+3m