19. -x-2 = 2/3x + 3
5/3 x + 3 = -2
5/3x = -5
x = -3
20. none are correct, you can double check me by plugging in the x and y values in the coordanates into the first problem none of them worked out in the first equasion so no need to test the second
21. -3 is the answer, capable of being done by using desmos
First, set 2x+7 equal to 3x-7 since they are the same angle due to the parallel lines.
2x+7=3x-7
x=14
Then, since 2x+7 and 12y+1 equals 180, put it together to find y:
(2x+7)+(12y+1)=180
(2(14)+7)+(12y+1)=180
12y+1=145
12y=144
y=12
So, x=14 and y=12. Your answer should be C!
I think it is b hope it helps
<span>Let the nickels be x and the dimes be y
x + y = 24
5x + 10y = 185
5x + 5y = 120
5y = 65
y=13
x=11
Answer: 11 nickels and 5 dimes</span>
6a. 1 - 2sin(x)² - 2cos(x)² = 1 - 2(sin(x)² +cos(x)²) = 1 - 2·1 = -1
6c. tan(x) + sin(x)/cos(x) = tan(x) + tan(x) = 2tan(x)
6e. 3sin(x) + tan(x)cos(x) = 3sin(x) + (sin(x)/cos(x))cos(x) = 3sin(x) +sin(x) = 4sin(x)
6g. 1 - cos(x)²tan(x)² = 1 - cos(x)²·(sin(x)²)/cos(x)²) = 1 -sin(x)² = cos(x)²
