20) m∠6 = m∠7 because they are vertical angles.
7x - 24 = 5x + 14
7x = 5x + 38
- Subtract 5x from both sides.
2x = 38
x = 19
- Plug 19 for x into either m∠6 or m∠7.
m∠6 = 7(19) - 24 = 109
m∠6 and m∠7 = 109°
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21) m∠4 + m∠5 = 90 because they are complementary angles.
(2x - 5) + (4x - 13) = 90
6x - 18 = 90
6x = 108
x = 18
- Plug 18 for x into m∠4 and m∠5.
m∠4 = 2(18) - 5 = 31°
m∠5 = 4(18) - 13 = 59°