Answer:
x = 10°
Step-by-step explanation:
The diagonals of a rhombus divide the figure into congruent right triangles. That means the two marked acute angles are complementary.
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Complementary angles total 90°, so the relation we can use to find x is ...
(3x -13) +(8x -7) = 90
11x = 110 . . . . . . . . . add 20
x = 10 . . . . . . . . . divide by the coefficient of x
The value of x is 10°.
Answer:1) commutative property of addition
1)247 + 211 = 458
2)458 - 211 = 247
