Объяснение:
1)a²-49=a²-7²=(a-7)(a+7)
2)64-b²=8²-b²=(8-b)(8+b)
3)c²-2,25=c²-(1,5)²=(c-1,5)(c+1,5)
4)2,89-d²=(1,7)²-d²=(1,7-d)(1,7+d)
5)64/81-x²=(8/9)²-x²=(8/9-x)(8/9+x)
6)100/121-y²=(10/11)²-y²=(10/11-y)(10/11+y)
7)x²-169/196=x²-(13/14)²=(x-13/14)(x+13/14)
8)t^2-400/441)=t²-20²=(t-20/21)(t+20/21)
9)25x²-36=(5x)²-6²=(5x-6)(5x+6)
10)-16+49y²=-(16-49y²)=-(4²-(7y)²=-(4-7y)(4+7y)
11)0,64-1/9x²=0,8²-(1/3x)²=(0,8-1/3 x)(0,8+1/3 x)
12)4/25 t²-36=(2/25 t)²-6²=(2/5 t-6)(2/5t+6)
Объяснение:
1)a²-49=a²-7²=(a-7)(a+7)
2)64-b²=8²-b²=(8-b)(8+b)
3)c²-2,25=c²-(1,5)²=(c-1,5)(c+1,5)
4)2,89-d²=(1,7)²-d²=(1,7-d)(1,7+d)
5)64/81-x²=(8/9)²-x²=(8/9-x)(8/9+x)
6)100/121-y²=(10/11)²-y²=(10/11-y)(10/11+y)
7)x²-169/196=x²-(13/14)²=(x-13/14)(x+13/14)
8)t^2-400/441)=t²-20²=(t-20/21)(t+20/21)
9)25x²-36=(5x)²-6²=(5x-6)(5x+6)
10)-16+49y²=-(16-49y²)=-(4²-(7y)²=-(4-7y)(4+7y)
11)0,64-1/9x²=0,8²-(1/3x)²=(0,8-1/3 x)(0,8+1/3 x)
12)4/25 t²-36=(2/25 t)²-6²=(2/5 t-6)(2/5t+6)