Question

можно с подробным решением​

Answer 1

1) x^2 - y^2
2) n^2 - m^2
3) k^2 - 4
4) 9 - c^2
5) 16 - b^2
6) a^2 - 49
7) 1/49 - x^2
8) a^2 - 4/81
9) 25/36 -m^2
10)
11) k^2 - 121/100
12) d^2 - 121/25

Answer 2

$1) (x+y)(x-y)=x^{2} -xy+xy-y^{2} =x^{2} - y^{2}$

$2) (n-m)(n+m)=n^{2} +mn- mn-m^{2} = n^{2} -m^{2}$

$3) (k-2)(k+2)=k^{2} +2k-2k-4=k^{2} -4$

$4) (3-c)(3+c)=9+3c-3c-c^{2} = 9-c^{2}$

$5) (4+b)(4-b)=16-4b+4b-b^{2}= 16-b^{2}$

$6) (a-7)(a+7)=a^{2} +7a-7a-49=a^{2} -49$

$7) (\frac{1}{7} + x) (\frac{1}{7} -x)= \frac{1}{49} - \frac{1}{7} x+\frac{1}{7} x-x^{2} = \frac{1}{49} - x^{2}$

$8) (a-\frac{2}{9} )(a+\frac{2}{9} )= a^{2} +\frac{2}{9} a-\frac{2}{9} a-\frac{4}{81} =a^{2} - \frac{4}{81}$

$9) (\frac{5}{6} + m)(\frac{5}{6} - m) = \frac{25}{36} -\frac{5}{6} m+\frac{5}{6} m-m^{2} = \frac{25}{36} - m^{2}$

$10) (0,4+n)(0,4-m)=0,16-0,4m+0,4n-mn$

$11) (k+1,1)(k-1,1)=k^{2} -1,1k+1,1k-12,1=k^{2} - 12,1$

$12) (d-2,2)(d+2,2)=d^{2} +2,2d-2,2d-4.84=d^{2} -4,84$