Question

упростите выраженияa) (6m^2-4m+9n)(-1/6m^2) b) 2a(a-b)-a(a-2b) d)(1+3a-a^4)×5a c)2/7x(1,4x^2-3,5y) e)-1/3c^2(1,2d^2-6c) a)-0,5x^2(2x^2+6x-7) b)-x(x^2-7)+x^2(x-3) d)3a^4x(a^2-2ax+x^3-1) e)1/2ab(2/3a^2-3/4ab+4/5b^2) c)-2/5a^2y^5(5ay^2-1/2a^2b-5/6a^3)

Answer 1

$a)(6m^2-4m+9n)\cdot(-\frac{1}{6}m^2)=-6m^2\cdot\frac{1}{6}m^2-4m\cdot(-\frac{1}{6}m^2)-9n\cdot\frac{1}{6}m^2=-m^2\cdot m^2+2m\cdot\frac{1}{3}m^2-3n\cdot\frac{1}{2}m^2=-m^4+\frac{2}{3}m^3-\frac{3}{2}m^2n\\b) 2a(a-b)-a(a-2b)=2a^2-2ab-a^2+2ab=a^2\\c)\frac{2}{7}\cdot(1,4x^2-3,5y)=\frac{2}{7}\cdot(\frac{7}{5}x^2-\frac{7}{2}y)=\frac{2}{5}x^2-y=\frac{2}{5}x^2-y\\d)3a^4x(a^2-2ax+x^3-1)=3a^4xa^2-3a^4x\cdot2ax+3a^4x\cdot x^3-3a^4x=3a^6x-6a^5x^2+3a^4x^4-3a^4x$

$e)\frac{1}{2}ab\cdot(\frac{2}{3}a^2-\frac{3}{4}ab+\frac{4}{5}b^2)=\frac{1}{2}ab\cdot \frac{2}{3}a^2-\frac{1}{2}ab\cdot\frac{3}{4}ab+\frac{1}{2}ab\cdot\frac{4}{5}b^2=ab\cdot\frac{1}{3}a^2-\frac{3}{8}a^2b^2+ab\cdot \frac{2}{5}b^2=\frac{1}{3}a^3b-\frac{3}{8}a^2b^2+\frac{2}{5}ab^3\\f)-\frac{2}{5}a^2y^5\cdot5(5ay^2-\frac{1}{2}a^2b-\frac{5}{6}a^3)=-2a^2y^5\cdot(5ay^2-\frac{1}{2}a^2b-\frac{5}{6}a^3)=-10a^3y^7+a^4by^5+\frac{5}{3}a^5y^5$