Answer: x = 2
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Step-by-step explanation:
The triangle is equilateral, so each side is the same length.
- equi = equal
- lateral = sides
Let's set the first two sides equal to one another and solve for x
side1 = side2
13 = 9x-5
9x-5 = 13
9x = 13+5
9x = 18
x = 18/9
x = 2 is the final answer
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Another approach is to set the last two sides equal to one another.
side2 = side3
9x-5 = 4x+5
9x-4x = 5+5
5x = 10
x = 10/5
x = 2
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Or another idea is to pair up the first and last sides.
side1 = side3
13 = 4x+5
4x+5 = 13
4x = 13-5
4x = 8
x = 8/4
x = 2
Either way, we get the same answer of x = 2 each time. This helps confirm we have the correct x value.