№1 Разложите на множители:1) 8(у-3)-а(3-у)2) 6(а-2)+5а(2-а)3) 2(х+у)(х-у)-(х+у)^24) 3ах-ау+3bх-bу5) ab-ac-7b+7c№2 выполните умножение:1) (3х-2у)(3х+2у)2) (z-4b)(4b+z)3) (-2n+3p^2)(3p^2+2n)4) (5a^2-0,4b^2)(0,4b^2+5a^2)5) (2,5x-0,3y)(2,5x+0,3y)

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вопрос

№1
1) 8(y-3)-a(3-y) = 8y - 24 - 3a + ay = 8y + ay - 24 - 3a
2) 6(a-2) + 5a(2-a) = 6a - 12 + 10a - 5a^2 = -5a^2 + 16a - 12
3) 2(x+y)(x-y) - (x+y)^2 = 2(x^2 - y^2) - (x^2 + 2xy + y^2) = 2x^2 - 2y^2 - x^2 - 2xy - y^2 = x^2 - 2xy - 3y^2
4) 3ax - ay + 3bx - by = 3ax + 3bx - ay - by = 3(a+b)x - (a+b)y = (3x-y)(a+b)
5) ab - ac - 7b + 7c = a(b-c) - 7(b-c) = (a-7)(b-c)

№2
1) (3x-2y)(3x+2y) = 9x^2 - 6xy + 6xy - 4y^2 = 9x^2 - 4y^2
2) (z-4b)(4b+z) = 4bz + z^2 - 16b^2 - 4b^2 = z^2 - 12b^2
3) (-2n+3p^2)(3p^2+2n) = -6np^2 + 9p^4 + 6np^2 - 4n^2 = 9p^4 - 4n^2
4) (5a^2-0.4b^2)(0.4b^2+5a^2) = 2a^2(0.4b^2) + 25a^4 - 0.4b^2(0.4b^2) - 2b^2(0.4b^2) = 5a^2b^2 + 25a^4 - 0.16b^4 - 0.8b^4 = 25a^4 - 0.96b^4 + 5a^2b^2
5) (2.5x-0.3y)(2.5x+0.3y) = 6.25x^2 - 0.75y^2