Дана функция f(x)= { -1/x-1 +1, если 2=3 а) найдите f(2), f(2,5), f(4) б) постройте график функции y=f(x)

3.15

a) ad - bd + 7а - 7b = d(a - b) + 7(a - b) = (a - b)(d+7)

в) ab + ac + 8b + 8с = a(b+c) + 8(b+c) = (b+c)(a+8)

д) аb - а +b -1 = a(b - 1) + (b - 1) = (b-1)(a+1)

ж) bс - c-6b + 6 = c(b-1) - 6(b–1) = (b–1)(c–6)

13.16

a) ху + уz+ х²+ хz = y(x+z) + x(x+z) = (x+z)(y+x)

в) m²+ bm + mn + bn = m(m+b) + n(m+b) = (m+b)(m+n)

д) а² - аb - 5а + 5b = a(a-b) - 5(a-b) = (a-b)(a-5)

ж) 7с² - 7сd -Зс + 3d = 7c(c-d) - 3(c-d) = (c-d)(7c-3)

и) х³ - Зх²+ х - 3 = x²(x-3) + (x-3) = (x-3)(x²+1)

л) а² - 5аb - 2а + 10b = a(a-5b) - 2(a-5b) = (a-5b)(a-2)

3.19

а) (а - 2)² - 9 = (a-2-3)(a-2+3) = (a-5)(a+1)

г) 9 - (у + 2)² = (3-y-2)(3+y+2) = (1-y)(y+5)

ж) 36х² - (3х - 1)² = (6x-3x+1)(6x+3x-1) = (3x+1)(9x-1)

3.30

а) (2а - 3b)²- (а + 2b)² = (2a - 3b - a - 2b)(2a-3b + a+2b) = (a-5b)(3a-b)

б) (x² -1)² - (3х²+ 2)² = (x²-1-3x²-2)(x²-1+3x²+2) = (-2x²-3)(4x²+1)