Number 2 is already a mixed number. But it says mixed number as a decimal. So -1 29/40 as a decimal is -1.725.
Draw the triangle and then use Pythagoras' theorem
distance =

= 19.70 (2dp)
486/900 = .54 = 54%. .......
Basically 1/2 equals 2 and times x equals 2x. X is a variable an unknown number so 2x +4 and that's how you get your answer