The square with a side length (x + 3) and an equilateral triangle with side lengths (3x-1) have the same perimeter what is the value of x? Help please

 x = 9/5 or  

35 1/5 is the perimeter of the square and the triangle.

Step-by-step explanation:

The square has 4 sides, so the perimeter of the square is 4(x+3)

The triangle has 3 sides so the perimeter is 3(3x-1)

The perimeters are equal, so 4(x+3) = 3(3x-1)

Solve by distributing and then

4x +12 = 9x - 3  subtract 4x from both sides and add 3 to both sides

4x-4x +12 -3 = 9x-4x -3 +3  cancel the zero sums and combine similar terms.

9 = 5x  divide both sides by 5

x =  9/5

Check:  4(9/5 +3) = 3[3(9/5) -1]

36/5 + 3   = [3( 27/5  -1 ]   27/5 -3  -3 equivalent -15/5  27/5 -15/5 = 12/5

36/5 = 3(12/5)  = 36/5   TRUE!  simplify to mixed numbers

35 1/5 is the perimeter of the square and the triangle.