PLIS NA JUTRO e,f,c,D tylko te (ale nie same odp.)

Odpowiedź:
[tex]c)\ \ (2t+1)(1-3t)=2t-6t^2+1-3t=-6t^2-t+1\\\\d)\ \ (3ab-7)(3-7ab)=9ab-21a^2b^2-21+49ab=58ab-21a^2b^2-21\\\\e)\ \ (-x+y)(5x+6y)=-5x^2-6xy+5xy+6y^2=-5x^2-xy+6y^2\\\\f)\ \ (x+5y)(7x-y)=7x^2-xy+35xy-5y^2=7x^2+34xy-5y^2[/tex]