Panjang diagonal2 suatu belah ketupat diketahui berturut -.turut 18 cm dan (2x+3) cm. jika luas belah ketupat tersebut 81 cm kubik, tentukan: a. nilai x b. panjang diagonal yg kedua
Rositasari24
L = d1 x d2 : 2 81 = 18 x (2x + 3) : 2 81 = 9 x (2x + 3) 81 : 9 = 2x + 3 9 - 3 = 2x 6 = 2x x = 6:2 = 3
diagonal 2 = 2x + 3 = 2 x 3 + 3 = 9
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dwisekar45
81 = 1/2 x 18 x (2x +3) 162 = 36x + 54 108 = 36x 3 = x
81 = 18 x (2x + 3) : 2
81 = 9 x (2x + 3)
81 : 9 = 2x + 3
9 - 3 = 2x
6 = 2x
x = 6:2
= 3
diagonal 2 = 2x + 3
= 2 x 3 + 3
= 9
162 = 36x + 54
108 = 36x
3 = x
d2 = 2x + 3 = 9