Question

зробити це завдання ​

Answer 1

Ответ:

Объяснение:

2mn-3m+2n

2×(-3)×(-5)-3×(-3)+2×(-5)=30+9-10=39-10=29

4x^2y-2xy^2

4×5^2×(-0.4)-2×5×(-0.4)^2=4×25×(-0.4)-2×5×0.16=100×(-0.4)-10×0,16=-40-1,6= -41,6

Answer 2

$\displaystyle\bf\\1)\\\\2mn-2m-m+2n=2mn-3m+2n\\\\m=-3 \ \ ; \ \ n=-5\\\\2mn-3m+2n=2\cdot(-3)\cdot(-5)-3\cdot(-3)+2\cdot(-5)=\\\\=30+9-10=29\\\\Otvet \ : \ 29\\\\2)\\\\-4x^{2} y+3xy^{2} +3x^{2} y-5xy^{2} +5x^{2} y=\\\\=(-4x^{2} y+3x^{2} y+5x^{2} y)+(3xy^{2} -5xy^{2} )=\\\\=4x^{2} y-2xy^{2} =2xy\cdot(2x-y)\\\\x=5 \ \ ; \ \ y=-0,4\\\\2xy\cdot(2x-y)=2\cdot 5\cdot(-0,4)\cdot\Big(2\cdot 5-(-0,4)\Big)=\\\\=-4\cdot(10+0,4)=-4\cdot10,4=-41,6\\\\Otvet \ : \ -41,6$