Presupun ca unitatea de masura este centimetrul.
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48x3-a+(9:3+15)=129 cm
48x3-a+(3+15)=129 cm
48x3-a+18=129 cm
144-a+18=129 cm
144-a=129 cm - 18
144-a=111 cm
144-111=a
a=33 cm
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L = Lungime
l = latime
P = Perimetru
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l=33 cm
L=33 cm x 3
L=99 cm
P = 99 cm x 2 + 33 cm x 2
P = 198 cm + 66 cm
P = 264 cm
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Sper ca te-am ajutat !