Answer:
101
Step-by-step explanation:
According to the Law of Cosines, for any △ABC with side lengths a, b, and c, a2=b2+c2−2bccosA; b2=a2+c2−2accosB; and c2=a2+b2−2abcosC
.
The Law of Cosines can be used because all three side lentghs are known.
Set up the equation for the Law of Cosines:
a2=b2+c2−2bccosA
Substitute the known values into the Law of Cosines:
312=222+182−2(22)(18)cosA
Square the values and multiply:
961=484+324−792cosA
Add:
961=808−792cosA
Subtract 808
from both sides:
153=−792cosA
Divide both sides by −792
:
153−792=cosA
According to this equation m∠A
is equal to the inverse cosine function of −153792
. Write this:
m∠A=cos−1(−153792)
Calculate the value of the inverse cosine −153792
on a calculator:
m∠A≈101°
Therefore, m∠A≈101°
.
Answer:
42%
Step-by-step explanation:
To find the percent of decrease first find the difference between 32.25 and 18.70.
32.25 - 18.70 = 13.55
Now divide this number by the original number, in this case 32.25, and then multiply the answer you get by 100.
13.55 / 32.25 = 0.42
Multiply this number by 100 to get the percentage.
0.42 * 100 = 42
<h2>Given :</h2>
<h2>Solution :</h2>
_____________________________
For the answer to the question above,
2x + 4y = –7 (1)
y = -1/2x + 5 (2)
Putting (2) into (1), we have:
-2x + 4(-1/2x + 5) = -7
-2x - 2x + 5 = -7
-4x = -7 - 5 = -12
x = -12/-4 = 3
y = -1/2(3) + 5 = -3/2 + 5 = 7/2
Therefore there is only one solution
I hoipe my answer helped you. Feel free to ask more questions. Have a nice day!
The square root of 625 is 25
