Well lets see. You have a total of 52 marbles. So all you would have to do would be to find the percent of 52 out of 60. This sounds confusing and I may not be completely right but I hope you give it a shot!
Answer:
x + y ≤ 12
Step-by-step explanation:
Inequality:
Not more than 12 means less than or equal to 12
x + y ≤ 12
Answer:
1.
8x + 6y = 28
9x + 3y = 39
Set to equal y.
8x + 6y = 28
6y = -8x + 28
y = -8/6x + 28/6
y = -4/3x + 14/3
9x + 3y = 39
3y = -9x + 39
y = -9/3x + 39/3
y = -3x + 13
Set equal to each other.
-4/3x + 14/3 = -3x + 13
Combine like terms.
5/3x = 25/3
Multiply by 3/5
x = 5
Plug x in.
y = -3(5) + 13
y = -15 + 13
y = -2
(5, -2)
2.
-2x - 9y = -3
-7x - 9y= -33
Set equal to y.
-2x - 9y = -3
-9y = 2x - 3
y = -2/9x + 3/9
y = -2/9x + 1/3
-7x - 9y= -33
-9y = 7x - 33
y = -7/9x + 33/9
y = -7/9x + 11/3
Set equal to each other
-2/9x + 1/3 = -2/9x + 1/3
0 = 0
infinitely many solutions
Answer is the first one on left
To find the mean you must add up all the numbers and divide by how many there are:
35 + 60 + x
_________ = 70
3
35 + 60 + x = 210
x = 65
He must score at least a 65 for a 70 average.
