1) 25х^2 - (х + у)^2 = (5x + y)(5x - y)
2) 100 - (3а + 7у)^2 = (10 - 3a - 7y)(10 + 3a + 7y)
3) 1 - (а^2 + в^2)^2 = (1 - a^2 - b^2)(1 + a^2 + b^2)
1) 25х^2 - (х + у)^2 = (5x + y)(5x - y)
2) 100 - (3а + 7у)^2 = (10 - 3a - 7y)(10 + 3a + 7y)
3) 1 - (а^2 + в^2)^2 = (1 - a^2 - b^2)(1 + a^2 + b^2)