Answer: 7a^2+2a+7
Step-by-step explanation:Distribute the Negative Sign:
=9a2+7a+8+−1(2a2+5a+1)
=9a2+7a+8+−1(2a2)+−1(5a)+(−1)(1)
=9a2+7a+8+−2a2+−5a+−1
Combine Like Terms:
=9a2+7a+8+−2a2+−5a+−1
=(9a2+−2a2)+(7a+−5a)+(8+−1)
=7a2+2a+7
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Answer: 72 HOPE THIS HELPS!
Angles in straight line add to 180 degrees
180-142=38
180-133=47
180-38-47=95
180-95=85 degrees
B