Cosθ = adjacent / hypotenuse

I hope I helped you^_^
Answer:
Solution to system is
x = 6 and y= 4
S.set={6,4}
Step-by-step explanation:
The given equations are
x + 3y = 18 ................(i)
x + 2y=14 .................(ii)
Subtracting both equation
(x+3y)-(x+2y)=18-14
x+3y-x-2y = 4
y = 4
put the value of y in equation (i)
the equation becomes
x + 3(4) = 18
x + 12 = 18
subtracting 12 from both sides
x + 12 -12 = 18-12
x =6
Solution to system is
x = 6 and y= 4
S.set={6,4}
74-17= 57 because if you subtract 10 from 74, it would be 64, then you need to subtract 7 from 64, which gives you 57.
9+7=16 because 10+7 would be 17, but since 9 is one less than 10, you need to subtract one from 17, which gives you 16.
17+(-30)=(-13) because adding 17 to -30 only brings up -30 to -13, and -30<-13.
-41+24=-17. Same reason as question 3, only different numbers.
-36+(-7)=-43 because adding two negatives together is like subtracting two positives from each other.
14+64=78 because adding 10 to 64 is 74 and 74+4=78.
-53-42=-95 because when you subtract a positive from a negative, it decreases the number even more.
-17-(-62)=45 because -62 is less than -17 and it is being subtracted from -17 so the answer becomes positive.
Hope this helps :)
Answer: <em>a + ( 2a - 7 ) = 41</em>
Explanation:
Let be "a" the Nicci's age and "s" the Nicci's sister.
You know that the sum of Nicci's age and her sister's age is 41. This can be represented with the following equation:
<em>a + 8 = 41</em>
And knowing that Nicci's sister is 7 years less than twice Nicci's age, you can write another equation to represent this:
<em>8 = 2a - 7</em>
Now, substitute the second equation into the first equation in order to find the equation that represents this relationship.
Then, this is:
<em>a + ( 2a - 7 ) = 41</em>
<em></em>
<em>Hope it helps...</em>
Answer:
if ∠ABC = 180°,
then, 2x∠ADC = ∠ABC ( angles subtended by an arc at the center is double the angle subtended it at any point on the remaining part if the circle)
{ please read the theorem carefully as i know u wont be able to understand it at first try :) }
therefore ∠ADC = 90°