Question

1.Suatu Persegi panjang diketahui ukuran panjangnya (4 + x)cm dan lebarnya ,x +5/2 cm.tentukan
-nilai x,jika kelilingnya 22cm.
-luas persegi panjang tsb.
no.5

Answer 1

P = (4+x) cm
l = (x+5/2) cm

k = 2(p+l)
22 = 2(4+x + x+5/2)
22 = 2(2(4+x)/2 + x+5/2)
22 = 2(8+2x/2 + x+5/2)
22 = 2(3x+13/2)
22 = 3x+13
22-13 = 3x
9 = 3x
9/3 = x
3 = x

p = 4+x = 4+3 = 7 cm
l = x+5/2 = 3+5/2 = 8/2 = 4 cm

L = p×l
= 7 × 4
= 28 cm²