Answer:
by SAS only
Step-by-step explanation:
based on the diagram we only have one side and one angle explicitly identified as equivalent.
but we have an implicit confirmation of the second side QS to the enclosed angle, because the triangles are presented that this side is the same for both triangles.
so, SAS applies (but no other, as we don't have any information on the 3rd side).
7 × x - 7 × 20
You could rewrite it this way, 7 x (x-20), but the answer above is better 'cause it takes away the grouping symbols
