Which property was used to simplify the expression? 3c+9+4c= 3c+4c+9
distributive property
commutative property
associative property
inverse property

The temperature of a chemical solution is originally 21 ? c . a chemist heats the solution at a constant rate, and the temperature of the solution 75 ? c after 1212 12 minutes of heating. the temperature, tt t , of the solution in ? c is a function of x , the heating time in minutes. write the function's formula.

What is the equation of the line that passes through (-3, -1) and has a slope of 2/5 ? put your answer in slope-intercept form. a y= 2/5x+1/5 b y=2/5x-1/5 c y=-2/5x-1/5

Abag contains 5 red marbles , 6 blue marbles and 4 green marbles. susie selects a marble and returns it to the bag before selecting another marble. if susie selects a red marble 6 out of 20 times, what is the experimental probability that the next marble she selects will be a red marble ?