X=(1800+600):30):560:(315:35)
X=(2400:30):560:9
X=80:560:9
X=80x1/560x1/9
X=1/7x1/9
X=1/63
A=58x72+63x81-58x52-63x61
= (58x72-58x52)+(63x81-63x61)
= 58(72-52)+63(81-61)
= 58x20+63x20
= 1160+1260
= 2420
B=87x96-27x13+13x27-87x86
= (87x96-87x86)-(27x13-13x27)
= 87(96-86)-27(13-13)
= 87x10 - 27x0
= 870-0
= 870
C= 53x39+87x39-53x31-47-21
= (53x39+87x39)-(53x31+47+21)
= 39(53+87)-(53x31+68)
= 39x140 - 53x31 -68
= 5460 - 1643 - 68
= 3749