Answer:
1 : 6
Step-by-step explanation:
Calculate the perimeter
perimeter = 2(3x + 5) + 2(6x + 10) = 6x + 10 + 12x + 20 = 18x + 30
perimeter = 18x + 30 ← take out a common factor of 6 from both terms
= 6(3x + 5)
ratio of width : perimeter
= 1(3x + 5) : 6(3x + 5) ← divide both parts by (x + 5)
= 1 : 6
