Answer:
a. [tex]\frac{x + 3}{21}=\frac{x + 1}{15}[/tex]
b. x = 4 (see steps below)
Step-by-step explanation:
Since the two polygons are similar, the sides are proportional to each other. Using a proportion, you can solve for 'x' using cross-multiplication and division:
[tex]\frac{smaller}{larger}=\frac{x + 3}{21}=\frac{x + 1}{15}[/tex]
Cross-multiply: 15(x + 3) = 21(x + 1)
Distribute: 15x + 45 = 21x + 21
Subtract '15x' from both sides: 15x + 45 - 15x = 21x + 21 - 15x or 45 = 6x + 21
Subtract '21' from both sides: 45 - 21 = 6x + 21 - 21 or 24 = 6x
Divide by 6 on both sides: 24/6 = 6x/6
Solve for x: x = 4
