Answer:
The student incorrectly used the Distributive property!
Step-by-step explanation:
The Distributive property says a(b+c)=ab+ac
In this problem the answer SHOULD be 3n-15, however the <u>student forgot to distribute the 3 to the -5</u>!
First you need to know that the internal angles of a triangle always equals 180°. Therefore:
15+45= 90°
Then since the angles should equal 180, you do:
180-90=90
So the missing angle equals 90°
Answer:
D. -9
Step-by-step explanation:
