PLease help! I will give you a lot of points and the brainiest! a. How many listened to only rock​ music?
n​(only ​rock)
b. How many listened to classical and​ jazz, but not​ rock?
n​(classical and​ jazz, not ​rock)
c. How many listened to classical or​ jazz, but not​ rock?
n​(classical or​ jazz, not ​rock)
d. How many listened to music in exactly one of the musical​ styles?
n​(exactly one ​style)
e. How many listened to music in exactly two of the musical​ styles?
n​(exactly two ​styles)
f. How many did not listen to any of the musical​ styles?
n​(none)

-2x + 7 = 7

subtract 7 from both sides.

-2x = 0

divide both sides by -2.

x = 0

the value of x is equal to 0.

Ok here we go ..there are plenty of ways to solve such math problems but we will go for the smartest and easiest ..5x+2y=7  -2x+6y=9we rearrange them into the following ..by multiplying the 1st equation by 2 it becomes 10x + 4y = 14we rearrange it and so it becomes 10x = 14 - 4yas for the second equation we multiply it by 5 and rearrange it so it becomes as to the following ..-10x + 30y = 45rearranging so 10x = 30y -45now 10x equals both 14 - 4y and 30y -45so   14 - 4y = 30y -4531 = 26yy= 31/26 = 1.19 or around 1.2so by now we can calculate x easily as  -2x+6y=9so 2x = 6y -9 = 6 * 31/26 - 9 = -1.84  then x = - 0.92 or around -0.9best luck!