-----------------------------------------------
Information Given:
-----------------------------------------------
ON = 7x - 9
LM = 6x + 4
MN = x - 7
OL = 2y - 7
-----------------------------------------------
Since it is a parallelogram:
-----------------------------------------------
ON = LM and
MN = OL
-----------------------------------------------
ON = LM:
-----------------------------------------------
7x - 9 = 6x + 4
-----------------------------------------------
Subtract 6x from both sides:
-----------------------------------------------
x - 9 = 4
-----------------------------------------------
Add 9 to both sides:
-----------------------------------------------
x = 13
-----------------------------------------------
MN = OL:
-----------------------------------------------
x - 7 = 2y - 7
-----------------------------------------------
Sub x = 13:
-----------------------------------------------
13 - 7 = 2y - 7
-----------------------------------------------
Simplify:
-----------------------------------------------
6 = 2y - 7
-----------------------------------------------
Add 7 on both sides:
-----------------------------------------------
13 = 2y
-----------------------------------------------
Divide by 2:
-----------------------------------------------
y = 13/2
-----------------------------------------------
Answer: x = 13, y = 13/2 (Answer D)
-----------------------------------------------
Given :
Challenge given is to volunteer for about 1 1/2 hours per week .
Autum did at a rate of 6 3/4 hours per week .
To Find :
The comparison ( ratio ) her volunteers rate with the challenge rate .
Solution :
Simplifying challenge rate in in normal fraction ,
.
Also , simplifying her rate ,
.
Now , ratio of his work by challenge is :

Therefore , the ratio is 9/2 or 4 1/2 .
Hence , this is the required solution .
So 5 liters of natural for every 7 synthetic, so 5 / 12 liters are natural oil.
so; 684 × (5/12) = 285 liters of natural oil
Hope this helps!
The answer would be 317d or you could
do 317(d)