<span>(u+3)(u+5)-(u+6)(u^2 - 6U+36)=u^2+8u+15-u^3-216=-u^3+u^2+8u-201</span>
u^2 + 8u + 15 - u^3 + 6u^2 - 36u - 6u^2 + 36u - 216 =
- u^3 + u^2 + 8u - 201
<u>21a^3b^5</u> = <u>3b^3</u>
35a^4b^2 5а