Question

Resolva essa equação do 2° Grau:
2(x-21)²=0

Answer 1

(2x -42) . (2x -42)
4x² -168x +1764 : 4
x² -42x +441 = 0

Δ = b² -4ac

(-42)² -4 . 441
1764 -1764
0

x = -b/2a
x = 42/2
x = 21