Question

look at the diagram. which equation can be used to solve for x? 21x = 84 x + 21 = 84 3(x + 7) = 84 3x + 7 = 84 solve for x. x =

Explanation:

Step1: Identify angle - sum relationship

The three angles \((x + 7)^{\circ}\) together make up the \(84^{\circ}\) angle. So the equation is \(3(x + 7)=84\).

Step2: Solve the equation for \(x\)

First, distribute the 3: \(3x+21 = 84\). Then subtract 21 from both sides: \(3x=84 - 21\), so \(3x = 63\). Finally, divide both sides by 3: \(x=\frac{63}{3}=21\).

Answer:

The equation is \(3(x + 7)=84\), \(x = 21\)