21 ÷ 3 - 35 + 7 × 28 = 224
(I) 21 ÷ 3 - 35 + 7 × 28 = 224
Interchanging ( × ) and ( - ) and applying BODMAS rule,
21 ÷ 3 × 35 + 7 - 28 = 224 7 × 35 + 7 - 28 = 224 245 + 7 - 28 = 224 252 - 28 = 224 224 = 224. LHS = RHS. (II) 21 ÷ 3 - 35 + 7 × 28 = 224
Interchanging ( + ) and ( × ) and applying
BODMAS rule,
21 ÷ 3 - 35 × 7 + 28 = 224
7 - 35 × 7 + 28 = 224
7 - 245 + 28 = 224
7 - 217 = 224
-210 ≠ 224.
LHS ≠ RHS.(III) 21 ÷ 3 - 35 + 7 × 28 = 224
Interchanging ( ÷ ) and ( × ) and applying
BODMAS rule,
21 × 3 - 35 + 7 ÷ 28 = 224
21 × 3 - 35 + 0.25 = 224
63 - 35 + 0.25 = 224
63 - 34.75 = 224
28.25 ≠ 224.
LHS ≠ RHS. (IV) 21 ÷ 3 - 35 + 7 × 28 = 224
Interchanging ( - ) and ( ÷ ) and applying
BODMAS rule,
21 - 3 ÷ 35 + 7 × 28 = 224
21 - 0.0857 + 7 × 28 = 224
21 - 0.0857 + 196 = 224
217 - 0.0857 = 224
216.9143 ≠ 224.
LHS ≠ RHS.Hence, the correct answer is
"× and -".