Sum/difference:
Let

This means that

Now, assume that
is rational. The sum/difference of two rational numbers is still rational (so 5-x is rational), and the division by 3 doesn't change this. So, you have that the square root of 8 equals a rational number, which is false. The mistake must have been supposing that
was rational, which proves that the sum/difference of the two given terms was irrational
Multiplication/division:
The logic is actually the same: if we multiply the two terms we get

if again we assume x to be rational, we have

But if x is rational, so is -x/15, and again we come to a contradiction: we have the square root of 8 on one side, which is irrational, and -x/15 on the other, which is rational. So, again, x must have been irrational. You can prove the same claim for the division in a totally similar fashion.
Answer:
[ See the attached picture ]
The diagonals of a parallelogram bisect each other.
✧ Given : ABCD is a parallelogram. Diagonals AC and BD intersect at O.
✺ To prove : AC and BD bisect each other at O , i.e AO = OC and BO = OD.
Proof :
♕ And we're done! Hurrayyy! ;)
# STUDY HARD! So, Tomorrow you can answer people like this , " Dude , I just bought this expensive mobile phone but it is not that expensive for me" [ - Unknown ] :P
☄ Hope I helped! ♡
☃ Let me know if you have any questions! ♪
☂
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Answer:
- 26 ounces of 55% solution
- 104 ounces of 80% solution
Step-by-step explanation:
Let x represent the quantity of 80% solution. Then 130-x is the amount of 55% solution. The total amount of salt in the mix is ...
0.80x +0.55(130 -x) = 0.75·130
0.25x = 0.20·130 . . . . . . . subtract 0.55(130)
x = 0.20/0.25(130) = 104
130-x = 26
She should use 26 ounces of 55% solution and 104 ounces of 80% solution.
Michael could save about 95 minutes by taking the train.