Odpowiedzi

2009-11-25T19:36:55+01:00
A) 2t-6t²+1-3t=-t-6t²+1
b)9ab-21a²b²-21+49ab=58ab-21a²b²-21
c)5x²+6xy-5xy-6y²=5x²+xy-6y²
d)7x²-xy+35xy-5y²=7x²+34xy-5y²
2009-11-25T19:38:35+01:00
A) (2t+1)(1-3t)=2t-6t²+1-3t=-t-6t²+1
b) (3ab-7)(3-7ab)=9ab-21ab²-21+49ab=58ab-21ab²-21
c) (x-y)(5x+6y)=5x²+6xy-5xy-6y²=5x²+xy-6y²
d) (x+5y)(7x-y)=7x²-xy+35xy-5y²=7x²+34xy-5y²