Question

what is the coefficient of x after simplifying (-x - 5)²?
○ -25
○ -10
○ 10
○ 25

Explanation:

Step1: Expand the square

We use the formula \((a + b)^2 = a^2 + 2ab + b^2\). Here, \(a=-x\) and \(b = - 5\), so \((-x-5)^2=(-x)^2+2\times(-x)\times(-5)+(-5)^2\)

Step2: Simplify each term

Simplify the terms: \((-x)^2=x^2\), \(2\times(-x)\times(-5) = 10x\), \((-5)^2 = 25\). So the expanded form is \(x^2+10x + 25\)

Step3: Identify the coefficient of \(x\)

In the polynomial \(x^2+10x + 25\), the coefficient of \(x\) is the number multiplied by \(x\), which is \(10\)

Answer:

10