Question

Use the identity (a + b)² = a² + 2ab + b² to expand the following expressions. 1.1 (x + 5)²​

Answer 1

The answer is:

⇨ x² + 10x + 25

Work/explanation:

Using the identity (a + b)² = a² + 2ab + b², I will simplify this.

`\sf{(x+5)^2}`

So not only do we square both terms, we take twice the product of these terms. And this is important.

With this in mind, I multiply and simplify.

`\sf{x^2+2*x*5+5^2}`

`\sf{x^2+10x+25}`

Hence, the right answer is x² + 10x + 25.

Answer 2

x² + 10x +25

Explanation:

Expanding the expression using identity:

(a + b)² = a² + 2ab + b²

a = x and b = 5. Substitute a = x and b =5 in the identity.

(x + 5)² = x² + 2*x *5 + 5²

= x² + 10x + 25