Solve the system of equations by finding the reduced row-echelon form of the augmented matrix for the system of equations. x + y - z = -2 2x - y + 3z = 9 x - 4y - 2z = 1

The perimeter of an equilateral triangle is 4 cm more than the perimeter of a square and the length of a side of the triangle is 8 cm more than the length of a side of the aware. find the length of a side of the equilateral triangle