8-2(n+3)=n+7-3n
We move all terms to the left:
8-2(n+3)-(n+7-3n)=0
We add all the numbers together, and all the variables
-2(n+3)-(-2n+7)+8=0
We multiply parentheses
-2n-(-2n+7)-6+8=0
We get rid of parentheses
-2n+2n-7-6+8=0
We add all the numbers together, and all the variables
-5!=0
There is no solution for this equation
With amounts measured in gallons, let
x = amount of 65% antifreeze
y = amount of 90% antifreeze
1 gal of the 65% brand contains 0.65 gal of pure antifreeze; x gal would contain 0.65x gal. Similarly, y gal of the 90% brand contains 0.90y gal of pure antifreeze.
To obtain 120 gal of 80% antifreeze solution (which contains 0.80•120 = 96 gal of pure antifreeze), we must have
x + y = 120 … … … … … [total volume of antifreeze solution]
0.65x + 0.90y = 96 … [total volume of pure antifreeze]
Solve the first equation for y :
y = 120 - x
Substitute this into the second equation and solve for x :
0.65x + 0.90 (120 - x) = 96
0.65x + 108 - 0.90x = 96
0.25x = 12
x = 48
Solve for y :
y = 120 - 48
y = 72
Answer:
1) y = 5/2x - 3/2
2) y = 2/5x - 4/5
Step-by-step explanation:
1)
(1, 1) and (3, 6)
m = (y2 - y1)/(x2 - x1)
m= (6 - 1)/(3-1)
m= 5/2
m= 5/2
y - y1 = m(x - x1)
y - 1 = 5/2(x - 1)
y - 1 = 5/2x - 5/2
y = 5/2x - 3/2
2)
(2, 0) and (7, 2)
m = (y2 - y1)/(x2 - x1)
m= (2 - 0)/(7 - 2)
m = 2/5
y - y1 = m(x - x1)
y - 0 = 2/5(x - 2)
y = 2/5x - 4/5
