Răspuns:
Explicație pas cu pas:
(x+4) + 5 = (x-5) (x+1) + 9
x + 4 + 5 = x^2 + x - 5x - 5 + 9
x + 9 = x^2 - 4x + 4
x^2 - 4x - x + 4 - 9 = 0
x^2 - 5x - 5 = 0
Δ = 25 + 20 = 45
x1 = (3 + √45)/2 = (3 + 3√5)/2
x2 = (3 - √45)/2 = (3 - 3√5)/2
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(2x+5)^2 + 3x = (8x-5)^2 +8 (x-2)
4x^2 + 20x + 25 + 3x = 64x^2 - 80x + 25 + 8x - 16
4x^2 + 23x + 25 = 64x^2 - 72x + 9
64x^2 - 4x^2 - 72x - 23x + 9 - 25 = 0
60x^2 - 95x - 16 = 0
Δ = 9025 + 3840 = 12865
x1 = (95 + √12865)/120
x1 = (95 + √12865)/120