А) -(4х-18) +18 = -4х+18+18 = -4х+36
б) (5-2b) - (7+10b) = 5-2b-7-10b=-2-12b
B) -(3c+5x)-(9c-6x)= -3c-5x-9c+5x+ -11x
Г) (2a-7y)-(5a-7y)= 2a-7y-5a+7y=-3a
Д)(11p+9c)-(12+11+9c) + 11p+9c -12 -11p-9c+= -12
e) x-(x-15)+(13+x)=x-x+15+13+x=x+28
Ж) (3а-21)-2а-(17-8а)= 3а-21-2а-17+8а=9а-38
з) (2-4b)-(31b-6)-11= 2-4b-31b+6-11= -35b-3
е) 14b-(15b+y)-(y+10b)= 14b -15b-y-y-10b=-11b-2y
X*0.15=2.4;
x=2.4/0.15;
x=16
Х²+<u>12х</u>+20 = х²+<u>2*6*х</u>+20 = х²+12х+20+16-16 = (х+6)² - 16<span>
x</span>²+12x+36 = (х+6)²
х²+<u>х</u>-2 = х²+2х-х-2 = х²+<u>2*1*х</u>-х-2 = х²+2х+1-1-х-2 = (х+1)² - х - 3
x²+2x+1 = (х+1)²
х²-<u>3х</u>-10 = х²-4х+х-10 = х²-<u>2*2*х</u>+х-10 = х²-4х+4-4+х-10 = (х-2)² + х - 14
x²-4x+4 = (х-2)²
х²-<u>2х</u>-35 = х²-<u>2*1*х</u>+20 = х²-2х-35+1-1 = (х-1)² - 36
x²-2x+1 = (х-1)²