Answer:
26°
Step-by-step explanation:
AC=tan 64
BC=x=sec 64
Using sine rule
(Sin 64)/tan 64 = (sin BAC)/sec 64
Cos 64 = (sin BAC)(cos 64)
Sin BAC= 1
BAC=90
ACB+ 64+90=180
ACB= 26°
Note that you are subtracting the same number from both sides. Thus, blank/100 must equal .26. Convert .26 to a fraction by placing it over 100 and removing the decimal point: 26/100. blank = 26
3 x - 7 = 5 x + 13
3 x - 5x = 13 + 7
-2x = 20
x = 20 / -2
x = - 10