A)10x²-(10x²-2x-15x+3)=31
10x²-10x²+2x+15x-3=31
17x=28
x=1,6
б)x²-3x-2x+6-(x²-5x+2x-10)=0
x²-5x+6-x²+3x+10=0
8x=-16
x=-2
Дано
N-40%
1000-100%
40*1000/100=400
N=400
M-18%
400-100%
18*400/100=72
M=72
P-15%
72-100%
72*15/100=10,8
P=10,8
ответ: Р=10,8
4a^3*b*12(ab^2)^2 = 48a⁵b⁵
Множители 7: 1*7, 7*1, (-1)*(-7), (-7)*(-1)
Запишем в систему
![\left \{ {{x-3=1} \atop {y+5=7}} \right. \to \left \{ {{x=4} \atop {y=2}} \right. \\ \\ \left \{ {{x-3=7} \atop {y+5=1}} \right. \to \left \{ {{x=10} \atop {y=-4}} \right. \\ \\ \left \{ {{x-3=-1} \atop {y+5=-7}} \right. \to \left \{ {{x=2} \atop {y=-12}} \right. \\ \\ \left \{ {{x-3=-7} \atop {y+5=-1}} \right. \to \left \{ {{x=-4} \atop {y=-6}} \right.](https://tex.z-dn.net/?f=+%5Cleft+%5C%7B+%7B%7Bx-3%3D1%7D+%5Catop+%7By%2B5%3D7%7D%7D+%5Cright.+%5Cto+%5Cleft+%5C%7B+%7B%7Bx%3D4%7D+%5Catop+%7By%3D2%7D%7D+%5Cright.++%5C%5C++%5C%5C++%5Cleft+%5C%7B+%7B%7Bx-3%3D7%7D+%5Catop+%7By%2B5%3D1%7D%7D+%5Cright.+%5Cto+%5Cleft+%5C%7B+%7B%7Bx%3D10%7D+%5Catop+%7By%3D-4%7D%7D+%5Cright.++%5C%5C++%5C%5C++%5Cleft+%5C%7B+%7B%7Bx-3%3D-1%7D+%5Catop+%7By%2B5%3D-7%7D%7D+%5Cright.+%5Cto+%5Cleft+%5C%7B+%7B%7Bx%3D2%7D+%5Catop+%7By%3D-12%7D%7D+%5Cright.++%5C%5C++%5C%5C++%5Cleft+%5C%7B+%7B%7Bx-3%3D-7%7D+%5Catop+%7By%2B5%3D-1%7D%7D+%5Cright.+%5Cto+%5Cleft+%5C%7B+%7B%7Bx%3D-4%7D+%5Catop+%7By%3D-6%7D%7D+%5Cright.+)
сумма чисел: 4+2+10+2=18