Answer:
(a) 10x -10 = 8x
Step-by-step explanation:
Given the lengths of corresponding sides in congruent triangles are 10x-10 and 8x, you want to know the correct equation needed to solve for x.
CPCTC
Corresponding parts of congruent triangles are congruent, so the corresponding sides (10x -10) and (8x) are the same length. The equation that expresses this relationship is useful for finding the value of x:
10x -10 = 8x
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Additional comment
The nature of the answer choices suggests that the values (10x-10) and (8x) could be considered to be the measures of the right angles. These two equations would give different values of x.
We interpret the figure as showing these expressions represent the lengths of the segments opposite the marked acute angles.
