Answer:
Step-by-step explanation:
First simplify:
Therefore we have:
![\sum\limits_{n=1}^{150}[-1-(n-1)]=\sum\limits_{n=1}^{150}(-n)=(-1)+(-2)+(-3)+...+(-150)\\\\-1,\ -2,\ -3,\ -4,\ ...,\ -150-\text{it's the arithmetic sequence}\\\text{with the common difference d = -1.}\\\\\text{The formula of a sum of terms of an arithmetic sequence:}\\\\S_n=\dfrac{a_1+a_n}{2}\cdot n\\\\\text{Substitute}\ n=150,\ a_1=-1,\ a_n=-150:\\\\S_{150}=\dfrac{-1+(-150)}{2}\cdot150=(-151)(75)=-11,325](https://tex.z-dn.net/?f=%5Csum%5Climits_%7Bn%3D1%7D%5E%7B150%7D%5B-1-%28n-1%29%5D%3D%5Csum%5Climits_%7Bn%3D1%7D%5E%7B150%7D%28-n%29%3D%28-1%29%2B%28-2%29%2B%28-3%29%2B...%2B%28-150%29%5C%5C%5C%5C-1%2C%5C%20-2%2C%5C%20-3%2C%5C%20-4%2C%5C%20...%2C%5C%20-150-%5Ctext%7Bit%27s%20the%20arithmetic%20sequence%7D%5C%5C%5Ctext%7Bwith%20the%20common%20difference%20d%20%3D%20-1.%7D%5C%5C%5C%5C%5Ctext%7BThe%20formula%20of%20a%20sum%20of%20terms%20of%20an%20arithmetic%20sequence%3A%7D%5C%5C%5C%5CS_n%3D%5Cdfrac%7Ba_1%2Ba_n%7D%7B2%7D%5Ccdot%20n%5C%5C%5C%5C%5Ctext%7BSubstitute%7D%5C%20n%3D150%2C%5C%20a_1%3D-1%2C%5C%20a_n%3D-150%3A%5C%5C%5C%5CS_%7B150%7D%3D%5Cdfrac%7B-1%2B%28-150%29%7D%7B2%7D%5Ccdot150%3D%28-151%29%2875%29%3D-11%2C325)
Answer:
$13.67
Step-by-step explanation:
Let's say that CD= c and DVDs= d. Four CDs and 4 DVDs cost $164, so the equation will be:
i. 4c + 4d= 164
The cost of the 4 CDs is half the cost of the 4 DVDs, to put into an equation it will be:
ii. 4c= 0.5(4d)
4c= 2d
d= 2c
Then we can substitute the second equation (ii) into the first equation (i). The calculation will be:
4c + 4d= 164
4c + 4(2c)= 164
4c+ 8c= 164
12c= 164
c=13.67
The cost for each CD is $13.67
Answer:
(-2,7) reflects to (-2,-7)
(3,9) reflects to (3, -9)
(7,2) reflects to (7,-2)
(-3,9) reflects to (-3,-9)
Step-by-step explanation:
in reflection across the x-axis the x value of the coordinate stays the same and the y value is negated to show it been reflected
Answer:
<h2>(-2, -4)</h2>
Step-by-step explanation:
Put the coordinates of the points to the equation, and check it:
(-4, -1) → x= -4, y = -1
L = -5(-4) - 3(-1) =20 + 3 = 23
R = 22
L ≠ R
(-1, -4) → x= -1, y = -4
L = -5(-1) - 3(-4) = 5 + 12 = 17
R = 22
L ≠ R
(-2, -4) → x= -2, y = -4
L = -5(-2) - 3(-4) = 10 + 12 = 22
R = 22
L = R CORRECT :)
(-4, -2) → x = -4, y = -2
L = -5(-4) - 3(-2) = 20 + 6 = 26
R = 22
L ≠ R
Answer:
Step-by-step explanation:
Drop an angle bisector from angle C until it intersects AB. Because of the symmetry of the triangles created, you will form two small right angle congruent triangles. Call the point of intersection with AB = D. In other words the bisector of <C is CD.
CB = AC Isosceles triangle
CD / CB = Sin(38.5)
CD=?
CB = 35
CD / 35 = Sin(38.5) Multiply both sides by 35
CD = 35 * sin(38.5)
CD = 21.79
BD/CB = Cos(38.5)
BD = CB* Cos(38.5)
BD = 35 * Cos (38.5)
BD = 27.39
Area = CD * BA/2
BA/2 = DB
Area = CD * BD
Area = 21.79 * 27.39
Area = 596.9
