(5k + 1,2t)^2 = 25k^2 + 12kt + 1,44t^2
(2/3a - 3/7b)^2 = 4/9a^2 - 4/7ab + 9/49b^2
(7/8c - 4/7d)^2 = 49/64c^2 - cd + 16/49d^2
Объяснение:
0,2(х-2)-0,3(2х-3) =0,2x-0,4-0,6х+0,9=0,5-0,4х
x^2+(y-2)^2=0