Answer:
Step-by-step explanation:
45+8x+21+90=180 degree(sum of interior angles of a triangle)
156+8x=180
8x=180-156
8x=24
x=24/8
x=3
Answer:37.2 sec
Step-by-step explanation:
Given
Joel takes 81 sec for 14 mile long track
speed of joel
mi/min=10.37 mi/min
Jason takes 69 sec for 14 mi track
so jason speed is 
if both starts from same spot in opposite direction then

where x is distance covered by Joel
then x=6.44 miles
therefore time required

0.000038 = 3.8e-5 = 3.8×10⁻⁵
Answer:
80 Students are in the band class
Step-by-step explanation:
I did this mentally so sorry if it is bad
16 = 20%
+
16 = 20%
= 40% 32 students
40% +40% = 80%
32+ 32 = 64
80+20%
64+16
80 Students are in the band class