Answer:
w = 98
Explanation:
Similar Triangles
The triangles RST and VSU are similar because sides VR and RS are congruent, and sides UT and TS are congruent also.
The scale factor of both triangles is 2, which means all side lengths of the smaller triangle are half their corresponding sides of the bigger triangle.
Following that, we have:
UV = 2RT
Substituting:
w - 40 = 2(w - 69)
Operating:
w - 40 = 2w - 138
Simplifying:
2w - w = 138 - 40
w = 98