Объяснение:
1)c²-0,49 =(с-0.7)(с+0.7)
2)16-k² =(4-k)(4+k)
3)400-m² =(20-m)(20+m)
4)t²-225 =(t-15)(t+15)
5)1,69-b² =(1.3-b)(1.3+b)
6)y²-16/81 =(y-4/9)(y+4/9)
7)25x^2-4=(5x-2)(5x+2)
8)25/36-64y(5/6-8y)(5/6+8y)
Объяснение:
1)c²-0,49 =(с-0.7)(с+0.7)
2)16-k² =(4-k)(4+k)
3)400-m² =(20-m)(20+m)
4)t²-225 =(t-15)(t+15)
5)1,69-b² =(1.3-b)(1.3+b)
6)y²-16/81 =(y-4/9)(y+4/9)
7)25x^2-4=(5x-2)(5x+2)
8)25/36-64y(5/6-8y)(5/6+8y)