Y = 4 is the answer.
Thanks (:
Given QR is congrent to LN and QR = 4x + 2 and LN = x + 7.
So, QR = LN
Hence, we can set up an equation as following:
4x + 2 = x + 7
4x + 2 - x = x + 7 - x Subtract x from each sides.
3x + 2 = 7 By simplifying.
3x + 2 - 2 = 7 - 2 Subtract 2 from each sides.
3x = 5
Divide each sides by 3 to isolate x.
So, 
Next step is to plug in
in QR = 4x+2 to get length of QR.
So, 
Since 2 can be written as 2/1.
By multiplying the second fraction by the common denominator 3.
By simplifying the second fraction.

So, 