Explain why one column in a hunderths grids is equal to one column in a tenths grid

The time spent dancing (minutes) and the amount of calories burned can be modeled by the equation c= 5.5t which table of values matches the equation and includes only viable solutions

Find the greatest common factor of the polynomial: 10x^5+15x^4-25x^3 10x^5 x^3 5x^3 5

Find the value of x for which the lines are parallel.