Given the original triangle and the scale triangle, you can determine that they are similar.
• Therefore, you can find the scale factor by dividing the lengths of the corresponding sides given in the exercise:
![\begin{gathered} sf=\frac{42\operatorname{cm}}{7cm} \\ \\ sf=6 \end{gathered}]()
• In order to find the value of "x", you need to multiply the corresponding side (whose length is 3 centimeters) by the scale factor:
![\begin{gathered} x=(3\operatorname{cm})(6) \\ \\ x=18\operatorname{cm} \end{gathered}]()
Hence, the answers are:
- Scale factor:

- Value of "x":
![x=18\operatorname{cm}]()