1.
a) 5763 + 1281 + 4637 + 2719
= (5763 + 4637) + (1281 + 2719)
= 10400 + 4000
= 14400
b) 1584 x 35 + 1584 x 70 - 1584 x 5
= 1584 x (35 + 70 - 5)
= 1584 x 100
= 158 400
c) 33 x 34 + 33 x 86 + 67 x 78 + 67 x 45
= 33 x (34 + 86) + 67 x (78 + 45)
= 33 x 120 + 67 x 123
= 3960 + 8241
= 12201
d) 4 x 35 x 9 + 2 x 36 x 18 + 3 x 29 x 12
= (4 x 35 x 9) + (2 x 36 x 18) + (3 x 29 x 12)
= 1260 + 1296 + 1044
= 3600
3.
a) 325 - 5 x (X - 1) = 300
5 x (X - 1) = 325 - 300
5 x (X - 1) = 25
(X - 1) = 25 : 5
X - 1 = 5
X = 5 + 1
X = 6
