Why can you multiply the numerator and the denominator of a fraction by the same number to find a equivalent fraction?

Asunflower was 20 1/2 inches tall. over the next 6 months, it grew to a height of 37 inches tall. what was the average yearly growth rate of the height of the plzzz write a proportion i will give you 100 points

Find the volume of the solid bounded by the plane z=0 and the paraboloid z=1-x^2 –y^2

Find the percent error of the measurement 4 cm