Keliling jajargenjang diketahui 36 cm. Jika panjang sisinya ( 2x + 5 ) cm dan ( x + 1 ) cm, tentukan A. Nilai x B. Panjang sisi jajargenjang

A). 36 = (2x + 5)+(x + 1)+(2x + 5)+(x + 1)
= 2× + × + 2× + × + 5 + 1 + 5 + 1
= 6× + 12
36 - 12 = 6×
24 = 6×
× = 24 ÷ 6
× = 4
B).sisi 1 = (2×4) + 5
= 8 + 5
=13
sisi 2 = 4 + 1
= 5