Answer:
or 
Step-by-step explanation:
we know that
Applying the law of cosines

In this problem we have



substitute the values



Answer:
999.60
Step-by-step explanation:
$3.51 times 42 is 147.42 and 1147.02 minus 147.42 is $999.60
TBH this might not be right I'm not great at math buuut- heeeyy
Answer:
<em>x </em>= 128°
Step-by-step explanation:
Its an isosceles triangle, so it has 2 two sides of equal length. and from here we can say that it has two angles that are the same, 26° and 26° we know that in a triangle there are 180° in total so we add up the two angles we know 26+26=52 and subtract it by 180 which equals 128°
Answer:
the question is incomplete, so I looked for a similar one:
<em>After the release of radioactive material into the atmosphere from a nuclear power plant, the hay was contaminated by iodine 131 ( half-life, 8 days). If it is all right to feed the hay to cows when 10% of the iodine 131 remains, how long did the farmers need to wait to use this hay? </em>
iodine's half life (we are given x, we need to find b):
0.5A₀ = A₀eᵇˣ
x = 8 days
we eliminate A₀ from both sides
0.5 = eᵇ⁸
ln 0.5 = ln eᵇ⁸
-0.69315 = b8
b = -0.69315 / 8 = -0.08664
since the farmers need to wait until only 10% of the iodine remains (we already calculated b, now we need to find x):
0.1A₀ = A₀eᵇˣ
0.1 = eᵇˣ
ln 0.1 = bx
where b = -0.08664
x = ln 0.1 / -0.08664 = -2.302585 / -0.08664 = 26.58 days