Answer:
x=15
Step-by-step explanation:
<GCB=180-5x
<EBA=9x
<DAC=8x
The sum of the three exterior angles equals 360.
(180-5x)+9x+8x=360
180-5x+9x+8x=360
-5x+9x+8x=360-180
12x=180
x=15
3/7 * -2 1/5 = (turn ur mixed number into an improper fraction)
3/7 * - 11/5 = (now just multiply straight across)
(3 * -11) / (7 * 5) = -33/35 <====