What is x equal to and why?

12 point are triangles pqr and stu congruent? what is the congruency that proves they are congruent? what is the perimeter of triangle pqr?

Yvaries directly as x. y =90 when x=6. find y when x=13

Add, subtract, multiply, or divide as indicated. list any restrictions for the variable(s) and simplify the answers when possible. 1) x-2 / x+5 + 3x / 2x-1 2) x+6 / x-6 - x^2 / x+6 3) x+9 / x-4 + x+2 / x^2-11x+28 4) x / x^2-64 + 11 / 2x^2+11x-40 5) 5 / x + 11 / x-3 - x-4 / x^2+2x-15