If = ⁻¹(7)+ ⁻¹(8)+ ⁻¹(18) , then is equal to

Step-by-step solution

It is given that, aligned & = ⁻¹(7)+ ⁻¹(8)+ ⁻¹(18) & = ⁻¹ ( 1 7 )+ ⁻¹ ( 1 8 )+ ⁻¹ ( 1 18 ) & = ⁻¹ ( 1 7 + 1 8 1- 1 7 8 )+ ⁻¹ 1 18 & = ⁻¹ ( 15 55 )+ ⁻¹ ( 1 18 )= ⁻¹ ( 3 11 + 1 18 1- 3 11 18 ) & = ⁻¹ ( 54+11 195 )= ⁻¹ ( 1 3 ) & = 1 3 =3 aligned Hence, option (2) is correct.