Please help me out with this

Which statement about perfect cubes is true

Which of the following is true about the graph of f(x)=7^x. select all that apply. a= it intercepts the x axis b=it intercepts both axis c=it intercepts neither d=it intercepts the y axis

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).