The sum of three expressions is 8 + 13a + 7a2. Two of them are 2a2 +

1.	The sum of three expressions is 8 + 13a + 7a2. Two of them are 2a2 + 3a + 2 and 3a2 – 4a + 1. Find the third expression.
Answer» Given that f he sum of 3 expressions is 8 + 13a + 7a² ……………..(1) Two of them are 2a² + 3a + 2 and 3a² – 4a + 1. ∴ The sum of above two expressions (2a² + 3a + 2) + (3a² – 4a + 1) = 2a² + 3a + 2 + 3a² – 4a + 1. = (2a² + 3a²) + (3a – 4a) + (2 + 1) = 5a² – a + 3 ∴ The required 3rd expression (1) – (2) (1) – (2) =(7a² + 13a + 8) – (5a² – a + 3) = 7a² + 13a + 8 – – 5a² – a – 3 =(7a² – 5a²) +(13a + a)+ (8 – 3) = 2a² + 14a + 5

The sum of three expressions is 8 + 13a + 7a2. Two of them are 2a2 + 3a + 2 and 3a2 – 4a + 1. Find the third expression.

Answer»

Given that f he sum of 3 expressions is 8 + 13a + 7a² ……………..(1)

Two of them are 2a² + 3a + 2 and 3a² – 4a + 1.

∴ The sum of above two expressions (2a² + 3a + 2) + (3a² – 4a + 1)

= 2a² + 3a + 2 + 3a² – 4a + 1.

= (2a² + 3a²) + (3a – 4a) + (2 + 1)

= 5a² – a + 3

∴ The required 3rd expression (1) – (2)

(1) – (2) =(7a² + 13a + 8) – (5a² – a + 3)

= 7a² + 13a + 8 – – 5a² – a – 3

=(7a² – 5a²) +(13a + a)+ (8 – 3)

= 2a² + 14a + 5