Question

(4 - x)^2 - 2x

answer the question ​

Answer 1

Answer- The above question is from the chapter 'Algebraic Expressions'.

Important identities:

1) (a+b)² = a² + 2ab + b²

2) (a-b)² = a² - 2ab + b²

3) (a+b) (a-b)= a² - b².

Let's take an example of (2-3)².

This is in the form (a-b)² where a= 2 and b= 3. By using identity of

(a - b)² = a² + b² - 2ab

            = 4 + 9 - 2 × 2 × 3

            = 1

Given question: Solve- (4 - x)² - 2x

Solution: (4 - x)² - 2x

The expression (4 - x)² is of the form (a-b)² where a= 4 and b= x.

So, (4 - x)² - 2x

= 4² + x² - 2 × 4 × x - 2x

= 16 + x² - 8x - 2x

= x² + 16 - 10x

∴ (4 - x)² - 2x = x² + 16 - 10x