36-n²=(6-n)(6+n)
0,757²-0,243²=(0,757-0,243)(0,757+0,243)=0,514*1=0,514
1/9х²-9=(1/3х-3)(1/3х+3)
(1/3х-3)(1/3х+3)=0
1/3х-3=0 1/3х+3=0
1/3х=3(*3) 1/3х=-3 (*3)
х=9 х=-9
6. (9х-7)²-(8х-6)²=(9х-7-8х+6)(9х-7+8х-6)=(х-1)(17х-13)
5. 121а²-144в²+77ав+84в²=11²а²-12²в²+7*11ав+7*12в²=(11²а²-12²в²)+7в(11а+12в)=(11а-12в)(11а+12в)+7в(11а+12в)=(11а+12в)(11а-12в+7в)=(11а+12в)(11а-5в)