Odpowiedź:
(4x + 1) × (x + 3) + 91 = (2x + 7) × (2x + 7)
4[tex]x^{2}[/tex] + 12x + x + 3 + 91 = 4[tex]x^{2}[/tex] + 14x + 14x + 49
94 - 49 = 4[tex]x^{2}[/tex] - 4[tex]x^{2}[/tex] + 28x - 12x - x
45 = 15x / ÷3
x = 3cm
Obw prostokąta = 2 × (4x + 1) + 2 × (x + 3) = 2 × (4 × 3 + 1) + 2 × (3 + 3) =
= 2 × 13 + 2 × 6 = 26 + 12 = 38cm
Obw kwadratu = 4 × (2x + 7) = 4 × (2 × 3 + 7) = 4 × 13 = 52cm
52cm - 38cm = 14cm
