Question

ПОМОГИТЕ!даю 35 баллов

Answer 1

$1); ; frac{12x+5y}{20x^2y}-frac{5y-4x}{25xy^2}=frac{5y(12x+5y)-4x(5y-4x)}{100x^2y^2}=\\=frac{60xy+25y^2-20xy+16x^2}{100x^2y^2}=frac{25y^2+40xy+16x^2}{100x^2y^2}=frac{(5y+4x)^2}{10^2x^2y^2}=(frac{5y+4x}{10xy})^2$

$2); ; frac{2n+3m}{12mn^2}-frac{9m-2n}{18m^2n}=frac{3m(2n+3m)-2n(9m-2n)}{36m^2n^2}=\\=frac{6mn+9m^2-18mn+4n^2}{36m^2n^2}=frac{9m^2-12mn+4n^2}{36m^2n^2}=frac{(3m-2n)^2}{6^2m^2n^2}= (frac{3m-2n}{6mn})^2$

Answer 2

(а)12х+5у)/20х²у-(5у-4х)/25ху²=

(5у(12х+5у)-(5у-4х)*4х)/100х²у²=

(60ху+25у²-20ху+16х²)/(10ху)²=

(16х²+40ху+25у²)/(10ху)²=((4х+5у/(10ху)²

б)(2n+3m)/12mn²-(9m-2n)/18m²n=

((2n+3m)*3m-(9m-2n)*2n)/36m²n²=

=(6mn+9m²-18mn+4n²)/(6mn)²=

(9m²-12mn+4n²)/(6mn)²=

((3m-2n)/(6mn))²