If r = 4 units and x = 13 units, then what is the volume of the cylinder

Three cylinders have a volume of 2836 cm^3. cylinder a has a height of 900 cm. cylinder b has a height of 225 cm. cylinder c has a height of 100 cm. find the radius of each cylinder. use 3.14 as an approximate for π

I’m really confused and need your assist me with this question i’ve never been taught

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?