Can someone me with these 4 geometry questions

When a formula is solved for a particular variable, several different equivalent forms may be possible. if we solved a=1/2bh for h, one possible correct answer is h=2a/b . which one of the following is not equivalent to this? a. h= 2(a/b) b. h= 2a(1/b) c. h= a/1/2b d. h= 1/2a/b

The cone in the diagram has the same height and base area as the prism. what is the ratio of the volume of the cone to the volume of the prism? h hl base area-b base area =b volume of cone_1 volume of prism 2 volume of cone 1 volume of prism 3 volume of cone 2 volume of prism 3 oc. od. volume of cone volume of prism e. volume of cone volume of prism 3 2

Using elimination, what is -4x+2y=-12 4x+8y=-24