Answer:
- Annie- 17 hours, Brian- 3 hours
Step-by-step explanation:
Let the number of hours Annie travelled be a, and same of Brian be b
<u>Then we have</u>
<u>Substituting a in the first equation</u>
- 5b + 2 + b = 20
- 6b = 20 - 2
- 6b = 18
- b = 3
<u>Then finding a</u>
<u>So the answer is:</u>
- Annie- 17 hours, Brian- 3 hours
x + 4 = 15
- 4 -4
x = 11
You would subtract 4 because you need to isolate the x to get the value of x. You would subtract it to both sides because whatever you do on one side, you have to do it to the other side.
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:
X=84
Step-by-step explanation:
180(the sum of the interior triangle angles) - [(180-130)+(180-134)]
