I think this is right. Hope it helps
Answer:
-1.66666666667 yards
Step-by-step explanation:
15x+12=6x-3
subtract 6x on both sides
9x+12=-3
subtract 12 on both sides
9x=-15
x=-1.6666666666667
B. 25 Km. The measure of BC is 25 km.
The easiest way to solve this problem is using the cosine theorem c = √a²+b²-2ab*cos A.
BC = √AC²+AB²-2(AC)(AB)*cos A
BC = √(21km)²+(14km)²-2(21km)(14km)*cos 89°
BC = √441km²+196km²-588km²*(0.017)
BC =√637km²-10.26km²
BC = √636.74km²
BC = 25.03km ≅ 25
(20 + 22 + 17) - 7 - 12 - (9 - x) = 37;
59 - 19 - 9 + x = 37;
31 + x = 37;
x = C) 6
Common difference of the arithmetic sequence, is

