(a+b)^(2)" formula "

The valency of an element A is 3 and that of another element B is 2 . The formula of the compound formed from A and B is ………….

The valencies of two elements A and B are given below : {:("Element",,"Valency"),(A,,1+),(B,,2+):} (i) What is formula of sulphate of A ? (ii) What is the formula of nitrate of B ?

At certain temperature, two moles of A combines with five moles of B to, produce two moles of C. If atomicity of A and B is 2, the formula of compound C is :

Use the formula : (a+b) (a-b) = a^(2) - b^(2) to evaluate : (iv) 9.8 xx 10.2

Use the formula : (a+b) (a-b) = a^(2) - b^(2) to evaluate : (vi) 4.6 xx 5.4

Use the formula : (a+b) (a-b) = a^(2) - b^(2) to evaluate : (I) 21 xx 19

Use the formula : (a+b) (a-b) = a^(2) - b^(2) to evaluate : (iii) 103 xx 97