Question

сделайте 3 и 4 пж пж пж пж пж пж пж пж пж ​

Answer 1

3.  

1)   .....=х²-7х-7х+49=х²-14х+49

2)   ....=a²-ab-ab+b²=a²-2ab+b²

3)   ....=m²+m-2m-2=m²-m-2

4)   ....= - 2x²+8x+3x-12= - 2x²+11x-12

5)   ....=3ab-18a²-5b²+30ab= - 18a² - 5b²+33ab

6)   ....=9m²+3mn-3mn-n²=9m² - n²

4.

$k^{6}n^{4} -k^{3}n^{2}=k^{3}n^{2} (k^{3}n^{2} -1)\\ \\ \\ 42a^{3}b^{4} -12abc=6ab(7a^{2} b^{3} -2c)\\ \\ \\ 3b+12-ab-4a=3(b+4)-a(b+4)=(3-a)(b+4)$