Answer pls i need help and don’t understand

Find the value of x for which line a is parallel to line b

The edge of a cube was found to be 30 cm with a possible error in measurement of 0.4 cm. use differentials to estimate the maximum possible error, relative error, and percentage error in computing the volume of the cube and the surface area of the cube. (round your answers to four decimal places.) (a) the volume of the cube maximum possible error cm3 relative error percentage error % (b) the surface area of the cube maximum possible error cm2 relative error percentage error %

The volume of a box varies directly with its length if a box in the group has a length of 30inches and k=24 what is its volume