Question

1. solve for x.

Explanation:

Step1: Recall angle - sum property

The sum of interior angles of a triangle is 180°. So, $(3x + 5)+(2x+10)+(x + 57)=180$.

Step2: Combine like - terms

Combine the x - terms and the constant terms: $(3x+2x + x)+(5 + 10+57)=180$, which simplifies to $6x+72 = 180$.

Step3: Isolate the variable term

Subtract 72 from both sides of the equation: $6x=180 - 72$, so $6x=108$.

Step4: Solve for x

Divide both sides by 6: $x=\frac{108}{6}=18$.

Answer:

$x = 18$