3. Panjang lintasan = 480 m jumlah putaran = 60 kali Keliling lingkaran = 480 m / 60 = 8 m Keliling = 2πr = 800 cm r = 8/2π = 8 / 2x3,14 = 1,27 m
4. panjang kerangka 1 balok = 4 (p+l+t) = 4 (7+3+5) = 4x15 = 60 cm untuk membuat 2 kerangka balok = 2x60 = 120 cm panjang kawat = 1,5 meter = 150 cm maka sisa kawat = 150 - 120 = 30 cm
5. Misalkan tambahan sapi = S, maka 30 x 80 = 20 x (80+S) 2400 = 1600 + 20S 20S = 2400-1600 20S = 800 S = 800/20 S = 40 ekor sapi
p = l+2
K = 2 (p+l) = 28
p+l = 28/2
p+l = 14 <--- substitusikan p=l+2
l+2+l = 14
2l = 14-2
l = 12/2
l = 6 cm (lebar)
p = l+2 = 6+2 = 8 cm (panjang)
Luas = p.l = 8x6 = 48 cm²
2. a= 2
b= 3
c = -9
x = (-b +/- √b²-4ac)2a
x = (-3 +/- √3²-4.2.-9)/2.2
x = (-3 +/- √9+72)/4
x = (-3 +/- √81)/4
x = (-3 +/- 9)/4
x1 = (-3 + 9)/4√= 6/4 = 3/2
x2 = (-3 - 9)/4 = -12/4 = -3
3. Panjang lintasan = 480 m
jumlah putaran = 60 kali
Keliling lingkaran = 480 m / 60 = 8 m
Keliling = 2πr = 800 cm
r = 8/2π
= 8 / 2x3,14
= 1,27 m
4. panjang kerangka 1 balok = 4 (p+l+t) = 4 (7+3+5) = 4x15 = 60 cm
untuk membuat 2 kerangka balok = 2x60 = 120 cm
panjang kawat = 1,5 meter = 150 cm
maka sisa kawat = 150 - 120 = 30 cm
5. Misalkan tambahan sapi = S, maka
30 x 80 = 20 x (80+S)
2400 = 1600 + 20S
20S = 2400-1600
20S = 800
S = 800/20
S = 40 ekor sapi