X = amount of 50% solution
y = total amount after mixing
Note that the amount of alcohol in the 20% solution is 80 (0.2) = 16 oz.
We have 2 unknowns, so we need 2 equations:
first, we can write the equation for the total volume:
y = x + 80
next, apply the percentages to get an equation for the amount of alcohol:
0.4 y = 0.5 x + 16
Finally, solve the pair of equations (in this case, by substitution of the 1st into the second:
0.4 (x + 80) = 0.5x + 16
0.4 x + 32 = 0.5X + 16
rearrange and combine like terms:
0.1x = 16
x = 160
from the 1st equation:
y = 160 + 80 = 240
Answer
(2,4)
Step-by-step explanation:
Answer:
x= 32 ± √29
Step-by-step explanation:
x² - 8x - 13 = 0
ax² + bx + c = 0
Comparing equations we get,
a=1
b=(-8)
c=(-13)
Using quadratic formula,
________
x= b² ± √ b²-4ac
—————————
2a
Substituting the values
__________
x= 64 ± √( 64 + 52)
______________
2
= 32 ± √29
Hope this answer helps you....
It is true sometimes because it only has one solution.
