The length of a rectangle is 6 less than 3 times it's width. The perimeter of the rectangle is 140 cm. Find the dimensions of mirectangle. (Use Cramer rule)
Mathématiques
asad81
Question
The length of a rectangle is 6 less than 3 times it's width. The perimeter of the rectangle is 140 cm. Find the dimensions
of mirectangle. (Use Cramer rule)
of mirectangle. (Use Cramer rule)
1 Réponse
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1. Réponse INSALYON80
Réponse :
l = 19 cm & L = 51 cm
Explications étape par étape :
length L = 3×l -6
perimeter p = 2L+2l = 2{3×l -6) + 2l = 8l - 12 = 140 ⇔ l = 152/8 = 19 cm
⇒ L = 3×19 -6 = 51 cm