-[-[(-3m-5n)-(-7n-5m)]+(4m+8n-9)]=-[-(-3m-5n+7n+5m)+4m+8n-9]=-[-(2m+2n)+4m+8n-9]=-(-2m-2n+4m+8n-9)=-(2m+6n-9)=-2m-6n+9
25x^2y-[5xy^2-(-10yx^2 + 7x^2y^2)-(3y^2x-11y^2x^2)]=25x^2y-(5xy^2+10yx^2-7x^2y^2-3y^2x+11y^2x^2)=25x^2y-(5xy^2+10yx^2-7x^2y^2-3y^2x+11y^2x^2)=25x^2y-(5xy^2+10yx^2+4x^2y^2-3y^2x)=15x^2y-2xy^2-4x^2y^2=-4x^2y^2+15x^2y-2xy^2
2a^2b-[-(3ab^2-0,4a^2b^2)+0,2a^2b]+\frac{2}{5}a^2b^2=2a^2b-(-3ab^2+0,4a^2b^2+0,2a^2b)+0,4a^2b^2=2a^2b+3ab^2-0,4a^2b^2-0,2a^2b+0,4a^2b^2=1,8a^2b-3ab^2=1,8*9(-\frac{1}{3})^2*2,5-3*(-\frac{1}{3})*2,5^2=\frac{9}{5}*\frac{1}{9}*2,5-6,25=\frac{1}{5}*\frac{25}{10}-6\frac{25}{100}=\frac{1}{5}*\frac{5}{2}-6\frac{1}{4}=\frac{1}{2}-6\frac{1}{4}=\frac{2}{4}-6\frac{1}{4}=-5\frac{3}{4}
-5x^2 -(- 2,3x^2y +1\frac{1}{2}xy) -3yx^2 - (2x^2 - 1,5xy)] = brakuje początkowego nawiasu [
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