terlampir yk_.
A.
K = 2 × (p + l)
94 = 2 × (5x + 2 + 2x + 3)
94 = 2 × (7x + 5)
94 = 14x + 10
14x = 94 – 10
14x = 84
x = 84/14
x = 6
p = 5x + 2
p = 5(6) + 2
p = 30 + 2
p = 32
l = 2x + 3
l = 2(6) + 3
l = 12 + 3
l = 15
B.
L = p × l
L = 32 × 15
L = 480 cm²
:)
- a. ukuran panjang dan lebar
p = 5x + 2
l = 2x + 3
—–
nilai x
K = 2p + 2l
94 cm = 2(5x + 2) + 2(2x + 3)
94 cm = (10x + 4) + (4x + 6)
94 cm = 14x + 10
94 cm – 10 = 14x
84 cm = 14x
x = 6 cm
Diperoleh :
panjang = 5x + 2 = 5(6) + 2 = 32 cm
lebar = 2x + 3 = 2(6) + 3 = 15 cm
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- b. luas persegi panjang
L = p × l
L = 32 cm × 15 cm
L = 480 cm²