Bantuin ya kak pke caranya no 18 sama 20

no 20 1/2 ×alas×tinggi 15×8:2 = 60

nomor 18
2/3 + 6/7 - 10/14 = 14/21 + 18/21 - 15/21 = 32/21 - 15/21 = 17/21 (D)
nomor 20
L segitiga = 1/2 x alas x tinggi = 1/2 x 8 x 15 = 60  (C)