Keliling suatu persegi panjang 98 cm. jika ukuran panjang adalah tiga kali lebarnya ditambah 5,maka luas persegi panjang tersebut adalah?
a.418 c.411 e.tulis sendiri kalo gk ada jawabannya b.415 d.155
zahraaryoko
K = 2p + 2l 98 = 2(3l+5) + 2l 98 = 6l + 10 + 2l 98 = 8l + 10 98 - 10 = 8l 88 = 8l l = 88/8 l = 11 cm p = 3l + 5 = 3(11) + 5 = 38 cm
Maka; L persegi panjang = p x l = 38 x 11 = 418 cm²
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danuef
P = 3x+5 l = x K = 2(p+l) 98 = 2(3x+5 + x) 98 = 2(4x + 5) 98 = 8x + 10 88 = 8x x = 11 p = 3x + 5 p = 3(11) + 5 p = 38 cm l = 11 cm Luas = p x l Luas = 38 x 11 Luas = 418 cm²
98 = 2(3l+5) + 2l
98 = 6l + 10 + 2l
98 = 8l + 10
98 - 10 = 8l
88 = 8l
l = 88/8
l = 11 cm
p = 3l + 5 = 3(11) + 5 = 38 cm
Maka;
L persegi panjang
= p x l
= 38 x 11
= 418 cm²
l = x
K = 2(p+l)
98 = 2(3x+5 + x)
98 = 2(4x + 5)
98 = 8x + 10
88 = 8x
x = 11
p = 3x + 5
p = 3(11) + 5
p = 38 cm
l = 11 cm
Luas = p x l
Luas = 38 x 11
Luas = 418 cm²