a) (7x-1)(2-x) = (x-3)(3-7x14x - 7x^2 - 2 + x = 3x - 7 - 21x + 21x^14x - 7x^2 - 2 + x = -30
-7x^2 + 15x - 2 = -3-7x^2 + 15x + 28 = 0
б) (a-3)(a+4) - (a+2)(a+7) при a = -1/(-1/8 - 3)(-1/8 + 4) - (-1/8 + 2)(-1/8 + 7(-25/8)(31/8) - (-15/8)(55/8-775/64 + 825/650/64 = 25/32
в) (m-n+10)(m+nm^2 - mn + 10m + mn - n^2 + 10m^2 - n^2 + 10m + 10m^2 - n^2 + 10(m + n)
a) (7x-1)(2-x) = (x-3)(3-7x
14x - 7x^2 - 2 + x = 3x - 7 - 21x + 21x^
14x - 7x^2 - 2 + x = -30
-7x^2 + 15x - 2 = -3
-7x^2 + 15x + 28 = 0
б) (a-3)(a+4) - (a+2)(a+7) при a = -1/
(-1/8 - 3)(-1/8 + 4) - (-1/8 + 2)(-1/8 + 7
(-25/8)(31/8) - (-15/8)(55/8
-775/64 + 825/6
50/64 = 25/32
в) (m-n+10)(m+n
m^2 - mn + 10m + mn - n^2 + 10
m^2 - n^2 + 10m + 10
m^2 - n^2 + 10(m + n)