A^2 - b^2 = (a-b)(a+b)
To test it, expand the right hand side.
Answer:
it is more likely that both of the students will be boys because there are 14 boys and 8 girls. 14 is greater than 8. So, both of the students that are chosen will be boys,
These lines are perpendicular!
y = x
y = -x–2
The slopes are reciprocals of each other, so they are perpendicular.
angle AOB = 132 and is also the sum of angles AOD and
DOB. Hence
angle AOD + angle DOB = 132° ---> 1
angle COD = 141 and is also the sum of angles COB and BOD. Hence
angle COB + angle DOB = 141° ---> 2
Now we add the left sides together and the right sides of equations 1 and 2
together to form a new equation.
angle AOD + angle DOB + angle COB + angle DOB = 132 + 141 ---> 3
We should also note that:
angle AOD + angle DOB + angle COB = 180°
Therefore substituting angle AOD + angle DOB + angle COB in equation 3 by 180
and solving for angle DOB:
180 + angle DOB = 132 + 141
angle DOB = 273 - 180 = 93°
