Odpowiedzi

2010-04-11T14:15:41+02:00
A = x - pierwszy bok
b = x+5cm - drugi bok
60 cm - obwód
P = ?

Obw. = 2a+2b
Obw = 2*x+2(x+5cm)
60cm = 2x+2x+10cm
4x=60cm-10cm
4x = 50cm
x = 12,5 cm
a = x = 12,5 cm
b = x+5cm = 12,5cm+5cm = 17,5

P = ab
P = 12,5cm*17,5cm
P= 218,75cm²

Odp. Pole prostokąta wynosi 218,75cm²
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Najlepsza Odpowiedź!
2010-04-11T14:20:03+02:00
A = b+ 5cm
b = ?
Ob = a+b
Ob = 60cm

2(a + b) = 60
2(b + 5 + b) = 60
2(2b + 5) = 60
4b = 60 - 10
4b = 50 \ :4
b = 12,5 cm

a = b + 5
a = 12,5 + 5
a = 17,5 cm

P = ab
P = 17,5 * 12,5
P = 218,75 cm2
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