Answer:
1. 30
2. 18
3. 460
4. 3
Explanation:
According to the hierarchy of operations, we first need to solve {},[] or () (starting by the inner ones). Then the multiplications and divisions and lastly we will add and subtract. Therefore we have:
(i) (45 x 2) ÷ [ 28 – { 14 + 9 } ]
(90) ÷ [ 28 – { 14 + 9 } ] solved the ()
(90) ÷ [ 28 – { 25 } ] solved the {}
(90) ÷ [ 3 ] solved the []
30.
ii) 72 ÷ [ 23 – { 4 + ( 3 x 5 ) }]
72 ÷ [ 23 – { 4 + ( 15 ) }] solved the ()
72 ÷ [ 23 – {19) ] solved the {}
72 ÷ 4 solved the []
18
(iii) 102 + 13 × 8 + 125 ÷ 5 × 10
102 + 104 + 25 x 10 Solved the first multiplication and division
102 +104 + 250 Solved the multiplication
460
(iv) 57 ÷ [ { ( 10 + 5) - 3 × 2 } + 10 ]
57 ÷ [ { 15 - 3 × 2 } + 10 ] solved the inner ()
57 ÷ [ { 15 - 6 } + 10 ] solved the multiplication
57 ÷ [ 9 + 10 ] solved the {}
57 ÷ 19 solved the []
3