Это все примеры на разность квадратов. Делаются одинаково:
a^2 - b^2 = (a - b)(a + b)
5) 2) (5 - m)(m + 5) = (5 - m)(5 + m) = 25 - m^2
4) (3 + x)(x - 3) = (x + 3)(x - 3) = x^2 - 9
7) 2) (1,5c+1 2/3 d)(1,5c-1 2/3 d) = (3c/2+5d/3)(3c/2-5d/3) =
= 9c^2/4-25d^2/9
4) (0,3a^3 - 1/7 n)(0,3a^3 + 1/7 n) = 0,09a^6 - n^2/49
9) 2) d^2 - 16 = (d - 4)(d + 4)
4) 25 - n^2 = (5 - n)(5 + n)
6) 9d^2 - 16 = (3d - 4)(3d + 4)
8) 25n^2 - m^2 = (5n - m)(5n + m)
10) 2) x^4*y^4 - 1 = (x^2*y^2-1)(x^2*y^2+1) = (xy-1)(xy+1)(x^2*y^2+1)
4) a^2*y^4 - 25 = (ay^2 - 5)(ay^2 + 5)
6) 100 - b^6 = (10 - b^3)(10 + b^3)
8) 16x^2*y^2 - 9b^6 = (4xy - 3b^3)(4xy + 3b^3)
11) 2) (x-y)^2 - 49 = (x - y - 7)(x - y + 7)
4) (2m-3n)^2 - 100n^2 = (2m-3n-10n)(2m-3n+10n) = (2m-13n)(2m+7n)
6) (2a+b)^2 - (2b+a)^2 = (2a+b-2b-a)(2a+b+2b+a) = (a-b)(3a+3b) =
= 3(a-b)(a+b)
15) 2) x^2 - 1/4 = 0
(x - 1/2)(x + 1/2) = 0
x1 = -1/2; x2 = 1/2
4) 0,04 - x^2 = 0
(0,2 - x)(0,2 + x) = 0
x1 = -0,2; x2 = 0,2