<span>C = AB + D
AB = C - D
B = (C-D)/A
B = C/A - D/A</span>
Answer:
Step-by-step explanation:
both angles must add up to 180 so
6x+12+3x+63 must =180
= 9x+75
9x+75=180
-75 -75
9x=105
x=11.66
meaning A is approximately 81.96
9514 1404 393
Answer:
y = 0
Step-by-step explanation:
Subtracting the right side gives ...

The factor multiplying y cannot be zero, so y must be zero.
(sqrt2 - sqrt6)/4 = - 0.259
cos ((7pi)/12) = cos 105 = - 0.259