Answer is x+9=11
6+x=9
x=3
15=x+12
x=3
7+x=10
x=3
x+9=11
x=2
So x+9=11 has a different x value than the rest of the equations. So it doesn't belong with the other three.
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
Y = 40
Since,
1st year = 200
2nd year= 200 + 40 =240
3rd year = 240 + 40 = 280
4th year = 280 + 40 = 320
5th year = 320 + 40 =360
6th year = 360 + 40 = 400.
So, basically all you have to do is add 40!
Therefore, the answer is y = 40 Hope this helped! :)