1)3(y-1)²+6y=3(y²-2y+1)+6y=3y²-6y+3+6y=3y²+3
2)8c+4(1-c)²=8c+4(1-2c+c²)=8c+4-8c+4c²=4+4c²
3)4ab+2(a-b)²=4ab+2(a²-2ab+b²)=4ab+2a²-4ab+2b²=2a²+2b²
4)3(x+y)²-6xy=3(x²+2xy+y²)-6xy=3x²+6xy+3y²-6xy=3x²+3y²
5)27.3ˇ4=3ˇ3.3ˇ4=3ˇ7=3.3.3.3.3.3.3=9.9.9.3=729.3=2187
6)(a³.b².c)ˇ4=aˇ12 . bˇ8 .cˇ4
Решение
x + y = 40
x*y = 364
y = 40 - x
x*(40 -x) = 364
x∧2 - 40x + 364 = 0
D = (40∧2 - 4*1*364 = 1600 - 1456 = 144
x1 = (40 - 12) / 2 = 14
x2 = (40 + 12) / 2 = 26
y1 = 40 - 14 = 26
y2 = 40 - 26 14
Ответ: (14; 26); (26;14)
Х² -5х+4=0
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У = п паровозык хавает бутер
А)c^2-4d^2=(с-2d)(c+2d)
б)-25a^2+10ab-b^2=-(25a²-10a+b²)=-(5a-b)²
<span>в)ax+by-ay-bx=(ax-ay)+(by-bx)=a(x-y)+b(y-x)=a(x-y)-b(x-y)=(a-b)(x-y)</span>