The question is asking to choose among the expression that represents the perimeter of the picture frame where as a rectangular picture frame has a width of 9cm and length of x cm and base on the fact, I would say that the answer would be 2x times 18. I hope you are satisfied with my answer
Answer:
(3x-1) (3x+1)
Step-by-step explanation:
9x^2-1
Rewriting as
(3x)^2 - 1^2
This is the difference of squares
a^2 - b^2 = (a-b)(a+b)
(3x-1) (3x+1)
Answer:
a. 
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:

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
Answer:
lala lala 4 yes did that work