Question

Zapisz w jak najprostszej postaci:

a) (a+3)(a-1)+(a-7)(a+5)

b) (2b-5)(3-2b)-(3b+2)(b-6)

c) -7c2(5c-4)+(3c2+c)(6-2c)

d) 3m(m-4)(5m+2)-m(2m+3)(4-3m)

e) -2x(3x-5y)-(x+2y)(3x-y)

Answer 1

a)  (a+3)(a-1)+(a-7)(a+5)= a^2-a+3a-3+a^2+5a+7a+-35=2a^2+14a-38

b)  (2b-5)(3-2b)-(3b+2)(b-6)=6b-4b^2-15+10b-3b^2-18b+2b-12=-7b^2-27

c) -7c2(5c-4)+(3c2+c)(6-2c)=35c^3+28c^2+18c^2-6c^3+6c-2c^2=-41c^3+44c^2+6c

d) 3m(m-4)(5m+2)-m(2m+3)(4-3m)=21m^3 - 53m^2 - 36m

e) -2x(3x-5y)-(x+2y)(3x-y)= -6x^2+10xy-3x^2+xy+6xy-2y^2= -9x^2 +17xy-2y^2

gdzie  x^2= x do 2 etc.