Please help i beg i never get these right

What should be done to solve the equation? x+14=21 add 14 to both sides of the equation. subtract 14 from the left side of the equation. add 14 to the left side and subtract 14 from the right side of the equation. subtract 14 from both sides of the equation.

Prove that quadrilateral is a rhombus.

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)