Докажите неравенство (b+2)(b+4)<(b+3)^2

Question

Докажите неравенство
(b+2)(b+4)<(b+3)^2

Answer 1

B^2+4b + 2b +8 < b^2+2b3+9
b^2+6b+8<b^2+6b+9

Answer 2

(b+2)(b+4)=b^2+4b+2b+8=b^2+6b+8
(b+3)^2=b^2+6b+9
В первом +8, а во втором +9...