Hi. Your answer is 5,700 because 685 is closer to 700 than 600. Please ask if you have any more questions. Also please mark as the brainliest answer!
Let's give the variable that you are trying to answer for a symbol. Let's call it X.
X = the amount of money both Greg and Thomas had in October
We know that in November, Greg added $120 to his account. So, Greg's account has: X + 120
We know that Thomas increased the money in his account by 20%, so Thomas' account has: X + 0.2X, or 1.2X
We know that these two amounts are equal:
X + 120 = 1.2X
Solve for X:
X + 120 - X = 1.2X - X
120 = .2X
120 / .2 = .2X / .2
600 = X
-35 is < -23.
-35 is less than -23.
-23 is closer to 0 on the number line with 12 steps than -35.
<h2><u>Answer:</u></h2>
x=(nπ/2)±15
x=(2nπ+90)/3
x=90-2nπ
<h2><u>Steps:</u></h2>
cos3x+sin2x-sin6x+cos5x=0
(cos3x+cos5x)+(sin2x-sin6x)=0
equation(1)
<u>Use formula:</u>


<u>So in equation (1),if c=3x ,d=5x,C=2x,D=6x</u>
》2cos{(c+d)/2}.cos{(c-d)/2}+2cos{(C+D)/2}.sin{(C-D)/2}=0
》2cos{(3x+5x)/2}.cos{(3x-5x)/2}+2cos{(2x+6x)/2}.sin{(2x-6x)/2}=0
》2cos(4x).cos(-x)+2cos(4x).sin(-2x)=0
》2cos(4x)[cos(-x)+sin(-2x)]=0
》2cos(4x)[cos(x)-sin(2x)]=0
<u>1)</u><u> </u><u>Either:</u>
2cos(4x)=0
cos(4x)=0/2
cos(4x)=0
cos(4x)=cos(90)
General solution for such case is:X=2n±a
So,
4x=2nπ±90
x=(2nπ±90)/4
x=(nπ/2)±15
<u>2) Or:</u>
cos(x)-sin(2x)=0
cos(x)=sin(2x)
General solution for such case is:X=2n±a
So,
x=2nπ±(90-2x)
x=2nπ±90±2x
x±2x=2nπ±90
<u>Take +ve sign,</u>
x+2x=2nπ+90
3x=2nπ+90
x=(2nπ+90)/3
<u>Take -ve sign,</u>
x-2x=2nπ-90
-x=2nπ-90
x=(2nπ-90)/(-1)
x=90-2nπ
Let $k = the monthly base fee.
The variable cost is $0.30 per minute.
Let
C = total cost in a month
x = minutes used
September:
x = 120 minutes
C = $50
Therefore
k + (0.30)(120) = 50
k + 36 = 50
k = $14
October:
x = 165 minutes
The cost is
C = 14 + (0.3)(165)
C = $63.5
Answer: $63.50