Can someone tell me the answers of this if you tell it correctly i will give brainless

Will give brainliest what is the value of x? enter your answer in the box.

What is the value of x in the equation7x+2y=48 when y=3

Abcd is reflected across the x- axis, then rotated 90 clockwise about the orgin, and finally reflected across the line y= x to form a’ b’ c’ .