Question

find bc
b • x+12 • c x+11 • d
←→ 13

Explanation:

Step1: Set up the equation

From the number line, we know that \( BC + CD = BD \). So, \( (x + 12)+(x + 11)=13 \).

Step2: Simplify the left - hand side

Combine like terms: \( x+12+x + 11=2x+23 \). So the equation becomes \( 2x + 23=13 \).

Step3: Solve for x

Subtract 23 from both sides: \( 2x=13 - 23=- 10 \). Then divide both sides by 2: \( x=\frac{-10}{2}=-5 \).

Step4: Find the length of BC

Since \( BC=x + 12 \), substitute \( x=-5 \) into the expression: \( BC=-5 + 12 = 7 \).

Answer:

7