X= a number
(2x+4)/3 + (x+2)= 20
Multiply everything by 3 to eliminate the fraction
(3/1)((2x+4)/3) + (3)(x+2)= (3)(20)
2x+4+3x+6= 60
5x+10=60
Subtract 10 from both sides
5x=50
divide both sides by 5
x=10
Check:
Substitute answer in original equation
(2x+4)/3 + (x+2)= 20
(2(10)+4)/3+(10+2)= 20
(20+4)/3+12= 20
24/3+12= 20
8+12= 20
20=20
Hope this helps! :)
Recall that for all t,
cos²(t) + sin²(t) = 1
Now,
x = 5 cos(t) - 7 ⇒ (x + 7)/5 = cos(t)
y = 5 sin(t) + 9 ⇒ (y - 9)/5 = sin(t)
so that substituting into the identity above, we get
((x + 7)/5)² + ((y - 9)/5)² = 1
which we can rewrite as
(x + 7)²/25 + (y - 9)²/25 = 1
(x + 7)² + (y - 9)² = 25
and this is the equation of a circle centered at (-7, 9) with radius 5.
Problem 7: Correct
Problem 8: Correct
Problem 9: Correct
The steps are below if you are curious
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Problem 7
S = 180*(n-2)
2340 = 180*(n-2)
2340/180 = n-2
13 = n-2
n-2 = 13
n = 13+2
n = 15
I'm using n in place of lowercase s, but the idea is the same. If anything, it is better to use n for the number of sides since S already stands for the sum of the interior angles. I'm not sure why your teacher decided to swap things like that.
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Problem 8
First find y
y+116 = 180
y+116-116 = 180-116
y = 64
which is then used to find x. The quadrilateral angles add up to 180*(n-2) = 180*(4-2) = 360 degrees
Add up the 4 angles, set the sum equal to 360, solve for x
x+y+125+72 = 360
x+64+125+72 = 360 ... substitution (plug in y = 64)
x+261 = 360
x+261-261 = 360-261
x = 99
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Problem 9
With any polygon, the sum of the exterior angles is always 360 degrees
The first two exterior angles add to 264. The missing exterior angle is x
x+264 = 360
x+264-264 = 360-264
x = 96
Answer:
The total members in the Spanish Club = 50
Step-by-step explanation:
Let the total members in the Spanish Club = x
Now, number of girls in the club = 30
Three-fifths of the members are girls.
⇒ 
of total members x = 30
or, 
Now, solving for x, we get:
or, x = 50
Hence,the total members in the Spanish Club = 50
Answer:
4
Step-by-step explanation:
9×3=27
2×7=14
1×4=4
nice logic
