Tìm x, y: a. (x + 1/2) - 3 = 3/4; b. 20/21 - (x - 14/2) - 3/4 = 3; c. 2 * (y + 1/2) - 3/4 = 3; d. 2/5 : 2 * y = 3/11

1. Tìm x, y
a. (x + 1/2) - 3 = 3/4
b. 20/21 - (x - 14/2) - 3/4 = 3
c. 2 * (y + 1/2) - 3/4 = 3
d. 2/5 : 2 * y = 3/11
2. Tính
a. 1/2 + 3/5 - 1/3
b. 0,125 + 7/2
c. 7/3 - 1/4
d. 2/15 * 3/7 + 3/5 : 7/8