Answer:
-5
Step-by-step explanation:
Distribute first: -2 + 2 - 4 -1 = -5
An angle bisector is a line passing through the vertex of the angle that cuts the angle into two equal smaller angles.
If MN is angle bisector, then
m∠JMN=m∠NMK.
The two smaller angles are adjacent angles, then
m∠JMK=m∠JMN+m∠NMK=2m∠JMN.
Divide this equality by 2:

Answer: 3x + 15 = 51
x is the number of laps that she swims on Monday, Wednesday, and Friday. Since she swims the same amount, we can multiply x by three. Since Saturday gives us an explicit answer, we can just add that to the equation.
Hope this helps :)