9514 1404 393
Answer:
- The angles are congruent, not supplementary. x = 20
- The angles are complementary, not supplementary. x = 17
Explanation:
1. The equation should be 5x = 100, because the marked angles are congruent.
Then, dividing by 5 gives ...
x = 100/5
x = 20
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2. The angles have a sum of 90°, not 180°. The correct equation is ...
3x +39 = 90
x + 13 = 30 . . . . divide by 3*
x = 17 . . . . . . . . subtract 13
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* Sometimes when the terms of the equation have the coefficient of x as a common factor, I like to divide by that first. It makes all of the numbers smaller, so more comfortable for me to deal with. The usual method would be to subtract 39 before doing the division. You get the same answer either way.