When two triangles are similar then the ratio of their corresponding sides are congruent.
Given, ΔPQR≈ΔXZY
Here QR is the corresponding side of YZ and QP is the corresponding side of ZX. Therefore,
[tex] \frac{5x+2}{7x} =\frac{21}{28} [/tex]
[tex] \frac{5x+2}{7x}*28x =\frac{21}{28} *28x [/tex] (Multiplying each sides by 28x)
(5x+2)*4=21*x
20x+8=21x (By distribution property)
8=21x-20x (Subtracting 20x from each sides).
8=x
So, the correct choice is D, ΔPQR≈ΔXZY, x=8.
