diketahui p = 12cm t = 4cm luas permukaan = 352cm berapakah lebar(l) nya

352 = 2(pxt) + 2(pxl) + 2(lxt)
352 = 2(12x4) + 2(12l) + 2(4l)
352 = 2(48) + 24l + 8l
352 = 96 + 32l
32l = 352-96
32l = 256
l = 256/32
l = 8 cm

luas permukaan = 2 (pl + pt + lt)
luas permukaan = 2 (12 l + (12×4) + (4 l)
352 cm² = 2 (48 + 16 l)
352 cm² = 96 + 32 l
352 - 96 = 32 l
256 cm  = 32 l
256 ÷ 32 = l
8 = l