Задание 1. Найдите корень уравнения.

1) $$(x-9)^2 - x^2 = 0 \implies x^2 - 18x + 81 - x^2 = 0 \implies -18x + 81 = 0 \implies 18x = 81 \implies x = 81/18 = 9/2 = 4.5$$.
2) $$(x-7)^2 - x^2 = 0 \implies x^2 - 14x + 49 - x^2 = 0 \implies -14x + 49 = 0 \implies 14x = 49 \implies x = 49/14 = 7/2 = 3.5$$.
3) $$(2x-3)^2 - 4x^2 = 0 \implies 4x^2 - 12x + 9 - 4x^2 = 0 \implies -12x + 9 = 0 \implies 12x = 9 \implies x = 9/12 = 3/4 = 0.75$$.
4) $$(2x-5)^2 - 4x^2 = 0 \implies 4x^2 - 20x + 25 - 4x^2 = 0 \implies -20x + 25 = 0 \implies 20x = 25 \implies x = 25/20 = 5/4 = 1.25$$.