A double replacement reaction occurs when the ionic parts of two ionic compounds are exchanged.
Reaction 1 results in a product which is a single compound. No ionic parts are exchanged.
Reaction 3 results in one compound being separated into its elemental parts. No ionic parts are exchanged.
Reaction 4 has two reactants, but Pb is an element and not an ionic compound. No ionic parts are exchanged.
Hence, the answer is Reaction 2. Both NaBr and Ca(OH)2 are ionic compounds. Br - is the anion in NaBr, and (OH)2 is also an anion. Ionic parts are exchanged.
The change in the y-variable would be decrease of 3.
The correct answer between all the choices given is the third choice or
letter C. I am hoping that this answer has satisfied your query about and it
will be able to help you.
Let's call 'it' x. 1/2 is equal to one third of x, so we could say that 1/3x = 1/2
Now we just have a simple equation to solve:
1/3x = 1/2
x = (1/2) / (1/3)
Dividing by a rational number (such as 1/3, which is expressed in fraction form) is the same as multiplying by its reciprocal (the reciprocal of a fraction is itself when the numerator and denominator have been swapped). Therefore
x = (1/2) / (1/3) = (1/2) * 3 = 3/2 = 1.5
To check this answer, test the statement. Half is a third of x, where x=1.5:
1.5 / 3 = 0.5 = 1/2
Answer:
55 because if u take the 6 and 3 and multiply then subtract 4 and whatever you get that's your answer same with the others