Question

1. solve for x.

Explanation:

Step1: Apply angle - sum property

The sum of interior angles of a triangle is 180°. So, $(x + 20)+(2x + 25)+(x+15)=180$.

Step2: Combine like - terms

Combine the x - terms and the constant terms: $(x+2x + x)+(20 + 25+15)=180$, which simplifies to $4x+60 = 180$.

Step3: Isolate the variable term

Subtract 60 from both sides: $4x+60 - 60=180 - 60$, resulting in $4x=120$.

Step4: Solve for x

Divide both sides by 4: $\frac{4x}{4}=\frac{120}{4}$, so $x = 30$.

Answer:

$x = 30$