diketahui balok abcd.efgh dengan panjang ab= (3× + 2) cm ,bc=14 cm ,dan cg=15 cm.jika luas permukaan balok tersebut 1.580 cm,volume balok abcd.efgh adalah ...cm

Lp = 2 (pl + pt + lt)
Lp = 2 ((3x+2)(14) + (3x + 2)(15) + (14)(15))
Lp = 2 (42x + 28 + 45x + 30 + 210)
1580 = 2 (87x + 268)
1580 = 174x + 536
174x = 1044
x = 1044 / 174
x = 6

→ P = 3x + 2 = 3(6) + 2 = 18 + 2 = 20
→ L = 14
→ t = 15

V = p x l x t
V = 20 x 14 x 15
V = 4200cm^3