Answer:
Sylvia=16
brother=8
Step-by-step explanation:
8+7=15
16-1=15
2y=10x-14
5x-y=7
Divide both sides by 2 in the 1st equation
y=5x-7
Now substitute is to 2nd equation
5x-5x+7=7
0=0
Therefore there is no solution or it is inconsistent

Step-by-step explanation:

Answer:
arc FD = 236°
Step-by-step explanation:
The measure of the arc is equal to the measure of the central angle it subtends, thus
arc FD = arc FE + arc ED = 146° + 90° = 236°