Korzystamy ze wzoru skróconego mnożenia:
(a + b)(a - b) = a² - b²
[tex]a) \ (10-s)(10+s) = 10^{2}-s^{2} = 100 - s^{2}\\\\b) \ (0,3x + 1,1y)(0,3x-1,1y) = 0,09x^{2}-1,21y^{2}\\\\c) \ (5u-2w)(2w+5u) = (5u-2w)(5u+2w) = 25u^{2}-4w^{2}\\\\d) \ (t+\frac{2}{3})(\frac{2}{3}-t) = (\frac{2}{3}+t)(\frac{2}{3}-t) = \frac{4}{9}-t^{2}[/tex]
[tex]e) \ (\frac{1}{5}a + 0,5b)(\frac{1}{5}a - 0,5b) = \frac{1}{25}a^{2}-0,25b^{2}\\\\f) \ (3c^{2}-d^{3})(3c^{2}+d^{3}) = 9c^{4}-d^{6}\\\\g) \ (0,2kl+2,2k^{2}l^{5})(0,2kl - 2,2k^{2}l^{5})=0,04k^{2}l^{2}-4,84k^{4}l^{10}\\\\h) \ (2m^{2}n + mn^{4})(mn^{4}-2m^{2}n)=(mn^{4}+2m^{2}n)(mn^{4}-2m^{2}n) = m^{2}n^{8}-4m^{4}n^{2}[/tex]
