Answer:
a
Step-by-step explanation:
X=-3 because first substitute the value of y into the original equation -2x-3=x+6 then isolate the variables -2x-x=6+3 which is -3x=9 then we can divide x=9/-3 which =-3
SinB = cosC = AC / BC = 8/10 = 4/5;
tgB = ctg C = AC/AB = 8/6 = 4/3, because we use T. Pitagora for calculating AB;
sinC = cosB = AB/ BC = 6/10 = 3/5;
tgC = ctgB = AB/ AC = 6/8 = 3/4.