Answer:
x = 51°
Step-by-step explanation:
The angle I shaded in yellow is a flat angle which measures 180°.
Use the 129° to find x.
180° - 129° = 51°
9514 1404 393
Answer:
B. (n²+n)/2
Step-by-step explanation:
You only need to try n=2 in the answer choices to determine which one gives a result of 3.
A. (2+1)/2 = 3/2 ≠ 3
B. (2² +2)/2 = 3 . . . . correct choice
C. (2² -2)/2 = 1 ≠ 3
D. (2 -1)/2 = 1/2 ≠ 3
_____
<em>Additional comment</em>
The differences of the sequence 1, 3, 6, 10, ... are increasing, not constant. This means the rule will not be linear, but will be 2nd degree. (Second differences are constant.) This eliminates choices A and D immediately.
Let's solve this:
I'm going to assume that -7/8x and those similar are (-7/8) times x and so on.
from first glance, the fourth equation looks like a failed attempt at a modifier of the first equation.
Start: First equation:
-(7/8)x - (3/4) = 20
multiply both sides of the equation by -1 to make it the 2nd equation:
(7/8)x + (3/4) = -(20)
or to get the third equation from the first, distribute the numerator in -(7/8)x outside the parentheses (remember: top/bottom = top times 1 over bottom) :
- 7(1/8)x - (3/4) - 20
equation 4 is weird (lets try to derive the first one from it):
-(7/8)(-8/7)x - (3/4) = 20(-8/7)
divide to 'get rid' of the (-8/7)
-(7/8)x - (3/4)/(-8/7) = 20
first and third terms are right but the second isn't; therefore, the 4th equation is the different one
<h3>
Answer: 24pi feet</h3>
Work Shown:
The area is 144pi square feet. So A = 144pi is plugged into the formula below to isolate r
A = pi*r^2
144pi = pi*r^2
144 = r^2 .... divide both sides by pi, the pi terms cancel
r^2 = 144
r = sqrt(144) ... take the square root of both sides
r = 12
This is plugged into the circumference of a circle formula
C = 2*pi*r
C = 2*pi*12
C = 2*12*pi
C = 24pi
This is approximately equal to 75.36 when you use the approximation pi = 3.14
Answer:
(44, - 27 )
Step-by-step explanation:
Given the 2 equations
5x + 8y = 4 → (1)
2x + 3y = 7 → (2)
Multiplying (1) by 2 and (2) by - 5 , then adding the result will eliminate x
10x + 16y = 8 → (3)
- 10x - 15y = - 35 → (4)
Add (3) and (4) term by term to eliminate x
y = - 27
Substitute y = - 27 into either of the 2 equations and solve for x
Substituting into (2)
2x + 3(- 27) = 7
2x - 81 = 7 ( add 81 to both sides )
2x = 88 ( divide both sides by 2 )
x = 44
solution is (44, - 27 )