1. Given any triangle ABC with sides BC=a, AC=b and AB=c, the following are true :
i) the larger the angle, the larger the side in front of it, and the other way around as well. (Sine Law) Let a=20 in, then the largest angle is angle A.
ii) Given the measures of the sides of a triangle. Then the cosines of any of the angles can be found by the following formula:
a^{2}=b ^{2}+c ^{2}-2bc(cosA)
2.
20^{2}=9 ^{2}+13 ^{2}-2*9*13(cosA) 400=81+169-234(cosA) 150=-234(cosA) cosA=150/-234= -0.641
3. m(A) = Arccos(-0.641)≈130°,
4. Remark: We calculate Arccos with a scientific calculator or computer software unless it is one of the well known values, ex Arccos(0.5)=60°, Arccos(-0.5)=120° etc
62%
of 25
'of' means multiplication.

Convert 62% to a decimal, divide it by 100(since percentages are parts of 100):
62/100 = 0.62

Multiply:
Answer:
1.98 × 10^10
Step-by-step explanation:
First solve for how many text messages were sent out per one month:
22,000,000 × 900
19,800,000,000
Convert into scientific notation:
1.98 × 10^10
In scientific notation, there can only be one number before the decimal. The rest of the numbers must be after the decimal; hence, why I put the numbers 9 and 8 after the decimal. If the rest of the numbers are zeros, you do not have to add them after the decimal. Instead, starting from right to left, count the number places until you reach your decimal. The number you have counted will be your exponent. I counted nine 0's, one 8, and one 9 which made this exponent 10 as there were 10 decimal placements.
The first one is $4 per bag, as given
For the he second one, you divide $15 by 4, you got $3,75 per bag
Therefore, the second one has the better unit price
Since its x + 3 we use -3
-3| 2 1 -8 21 (these are the # without the x)
___________________
-6 15 -21
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2 -5 7 0
Drag the 2 down, multiple it by -3 to get -6
1+(-6) = -5. -5 * -3 =15 . 15+(-8) = 7
7*-3 = -21. -21 +21 = 0
Since last # is 0 we have a factor.
factor is 2x^2 -5x -7 (we start with a power 1 less the original.)
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