We have 55% and 80% antifreeze. We need 90 gallons of 75%.
F - 55% and E - 80%
A) F + E = 90
B) .55 F + .80 E = 67.50 (which is .75 * 90) Multiplying A) by -.55
A) -.55 F -.55 E = -49.50 (which is -.55 * 90) then adding A) & B)
.25 E = 18
E = 72 gallons of 80% and
F = 18 gallons of 55%
********* DOUBLE CHECK ******************
72 * .80 = 57.60 and 18 * .55 = 9.90
57.60 + 9.90 = 67.50 gallons of antifreeze and we have 90 total gallons
(67.50 / 90) * 100 = 75% correct!
Source: 1728.com/mixture.htm
For the first one it is x= (y+3)/4
The distance between points 
and 
can be calculated using formula
1.
2.
3.
Then
Answer: correct choice is C.
Answer:
you can't
Step-by-step explanation:
Answer:
-(4x + 7)/2 - (3x - 2)/2 = (-4x - 7 - 3x + 2)/2 = (-7x - 5)/2
