Which expression is equivalent to (r-7)^6 ?

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction