Answer:
x=5
Step-by-step explanation:
9x^2 - 2x + 25 = 8x^2 + 8x
9x^2-8x^2-2x-8x+25=0
x^2-6x+25=0 factorize
(x-5)(x-5)=0
x-5=0 then x=5
4/5/8/87/7/9 is the answer
ANSWER
D. 4 minutes 40 seconds
EXPLANATION
The given data set showing the number of seconds of each song the playlist is:
283,204,198,229,173,230,168,236,215,204
Let the length of the 11th song be x.
Because he wants the mean to be 3 minutes 40 seconds, which is equal to 220 seconds, we write and solve the following equation for x.





We convert 280 seconds to minutes.

The correct choice is D
Answer:
x = -2 y= -8 and 8
Step-by-step explanation:
Since there is an equal number of y's, they cancel out when subtracting. You can put either equation on top. You will get same answer.
<u>To find x:</u>
<u>If you do (3x - 2y = 10) - (5x + 2y = 6),</u> you will get -2x=4. Divide both sides by -2, and get x = -2.
<u>If you do (5x + 2y = 6) - (3x - 2y = 10)</u>, you will get 2x=-4.Divide both sides by 2, and get x = -2.
<u>To find y:</u>
Substitute -2 for x in either equation. It doesn't matter.
<u>For 3(-2) - 2y = 10:</u>
3(-2) - 2y = 10 ––Multiply
-6 - 2y =10 ––Add 6 to both sides to get y alone
-2y = 16 ––Divide by -2
y = -8
<u>For 5x + 2y = 6:</u>
5(-2) + 2y = 6 ––Multiply
-10 + 2y = 6 ––Add 10 to both sides to get y alone
2y = 16 ––Divide by 2
y = 8