Question 246291
your equation is:


40a^8 + 16a^7 + 25a^9


this would be equivalent to:


a^7 * (40a + 16 + 25a^2)


expand this out again, and you get:


(a^7 * 40*a) + (a^7 * 16) + (a^7 * 25 * a^2)


a^7 * a = a^(7+1) = a^8
a^7 * a^2 = a^(7+2) = a^9


your equation becomes:


(40*a^8) + 16*a^7) + 25*a^9) which becomes:


40a^8 + 16a^7 + 25a^9


since we're back to the original equation, we're good.