АЛГЕБРА СОР 7КЛАСС, СДЕЛАЙТЕ ТО ЧТО СМОЖЕТЕ ​

ax + ay + b(x+y) = a(x + y) + b(x + y) = (a + b)(x + y)

xz + yz - 2xt - 2yt = z(x + y) - 2t(x + y) = (z - 2t)(x + y)

ax² - ay² - bx² - cx² + by² + cy² = a(x² - y²) - b(x² - y²) - c(x² - y²) = (a - b - c)(x² - y²) = (a - b - c)(x - y)(x + y)

a⁴ - a³ + a - 1 = a³(a - 1) + 1(a - 1) = (a³ - 1)(a - 1) = (a - 1)(a - 1)(a² + a + 1)

x² - y² + yz + xy + xz - xy = (x - y)(x + y) + y(z + x) + x(z - y) = (x + y)(x - y + z)

(a+b+c)³-a³ - b³ - c³ = 3a²b + 3a²c + 3ab² + 6abc + 3ac² + 3b²c + 3bc² = 3(a + b)(a + c)(b + c)

Объяснение:

200. 1) 2x+x=18 => 3x=18 => x=6

2) 7x+2x=27 => 9x=27 => x=3

3) 7+18 =3x+2x => 25=5x => x=5

4) 0,2x+1,1x = -2,7+1,4 => 1,3x=-1,3 => x=-1

5) 5,4 +3,6 = 0,3x+1,5x => 9=1,8x => x=5

6) 3/8x-1/6x=-15+10 =>( 9x-4x)/24 =-5 => 5x/24=-5 => 5x=-120 => x=-24

201.

1) 3x-6=x+2 => 3x-x = 6+2 => 2x=8 => x=4

2) 5-2x+2=4-x => 7-2x=4-x => 7-4 = 2x-x => x=3

3) 7x+1-9x-3=5 => -2x-2=5 => -2x=7 => x= -3,5

4) 3,4+2y=7y-16,1 => 3,4 +16,1 = 5y => 19,5=5y => y= 3,9

5) 1,4-0,4y=2,3-0,3y+1,8 => 0,3y-0,4y=2,3+1,8-1,4 => -0,1y=2,7 => y= -27

6)  2x/9-2/6=4x+5/2 => 2x/9-4x=5/2+2/6 => (2x-36x)/9=17/6 => -34x/9=17/6 => -34x=17*9/6 => -34x=25,5 => x=-0,75