Question

1.suatu persegi kelilingnya (40+3x)cm.jika panjag sisinya (x+3), maka luas persegi adalah...

Answer 1

Keliling = 4s
40+3x = 4(x+3)
40+3x = 4x+12
40-12 = 4x-3x
x = 28
panjang sisi = x+3 = 28 +3 = 31 cm
luas = s x s = 31 x 31 = 961 cm²

Answer 2

K persegi = 4s
L persegi = s²

40 + 3x = 4(x+3)
40 + 3x = 4x + 12
4x - 3x = 40 - 12
x = 28

s = x + 3
   = 28 + 3
   = 31 cm

Luas = (31 cm)²
        = 961 cm²