21y³+7y²-45y-15=7y²(3y+1)-15(3y+1)=(3y+1)(7y²-15)
1 + (2+3+4)*(5+6) = 1 + 9*11 = 100
или так
<span>-1*2 + 3 * (4 + 5*6) = -2 + 3*34 = 100</span>
1) (-a)^2*a^3 = a^2*a^3 = a^5
2) -a^2*a^3 = -a^5
3) a^2*(-a)^3 = a^2*(-a^3 ) = -a^5
4) -a^2*(-a)^3 = -a^2*(-a^3 ) = a^5