1) (6a-7)(6a+7)
2) (5y-9)(5y+9)
3) (47-37)(47+37)=840
4) 1/9b²
5) (8-5x)(8+5x)
6) (4b-7a)(4b+7a)
7) (53-63)(53+63)=-1160
8) 1/49•(5-7p)(5+7p)=49:(5-7p)(5+7p)
1) (6a-7)(6a+7)
2) (5y-9)(5y+9)
3) (47-37)(47+37)=840
4) 1/9b²
5) (8-5x)(8+5x)
6) (4b-7a)(4b+7a)
7) (53-63)(53+63)=-1160
8) 1/49•(5-7p)(5+7p)=49:(5-7p)(5+7p)