1) (x+3) ^2-1; 2) 49x^2- (y+8x) ^2; 3) 9- (7+3a) ^2; 4) (a+b) ^2- (b-c) ^2; 5) (4a-3) ^2-16; 6) (2b-25) ^2-36; 7) p^2- (2p+1) ^28) (m+n) ^2- (m-n)…

1) (x+3) ^2-1=х^2+6x+9-1=x^2+6x+8; 2) 49x^2- (y+8x) ^2=49x^2-y^2-16x+64x^2=113x^2-y^2-16x; 3) 9- (7+3a) ^2=9-49-42a-9a^2=-40-42a-9a^2; 4) (a+b) ^2- (b-c) ^2=a^2+2ab+b^2-b^2+2bc-c^2=a^2+2ab+2bc-c^2=(a^2-c^2)+2b (a+c)=(a+c) (a-c+2b); 5) (4a-3) ^2-16=16a^2-24a+9-16=16a^2-24a-7; 6) (2b-25) ^2-36=4b^2-100b+625-36=4b^2-100b+589; 7) p^2- (2p+1) ^2=p^2-4p^2-8p-1=-3p^2-8p-1; 8) (m+n) ^2- (m-n) ^2=m^2+2mn+n^2-m^2+2mn-n^2=4mn; 9) 9y^2- (1+2y) ^2=9y^2-1-4y-4^2=5y^2-4y-1; 10) (4-11m) ^2-1=16-88m+121-1=136-88m; 11) (2x+y) ^2- (x-2y) ^2=4x^2+4xy+y^2-x^2+4xy-4y^2=3x^2+8xy-3y^2; 12) (4c-x) ^2- (2c+3x) ^2=16c^2-8cx+x^2-4c^2-12cx-9x^2=12c^2-20cx-8x^2;