1. What is the concentration of the mixed solution? Total salt/total solution

So the total salt content is a% m+b% n.

Total solution m+n

See the answer in the picture below! !

2.

(1)y is a positive number (give you a formula? If a/b >; 0 then a * b > 0)

Y= radical number x/2x+1> 0

Root number x*(2x+ 1)>0

Because the root number x≥0

So 2x+1>; 0

X>- 1/2 and x≠0.

(2)

Same as (1)

get

Root number x * (2x+ 1) < 0

Because the root number x≥0

So 2x+ 1

x & lt- 1/2

3.

Let x/2=y/3=z/4=k, then x = 2k, y = 3k and z = 4k?

x+y-z/x+y+z =(2k+3k-4k)/(2k+3k+4k)= 1/9

The value obtained by substituting into the formula is 1/9?

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