Answer:
20. 4n+5+8n-5=180(linear pair)
12n=180
n=15
21. 9x-6=8.5x+2(can be seen from image)
9x-8.5x=2+6
0.5x=8
x=8/0.5
x=80/5
x=16
22. 4z+3z+6=90°(Complementary)
7z+6=90°
7z=84°
z=12°
Answer: Decrease
Step-by-step explanation:
Number of combinations of 5 women from 7 = 7C5 = 7*6 / 2 = 21
for men its 7C4 = 7*6*5 / 3*2 = 35
Total number of ways = 21*35 = 735