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.
B, n to the 3rd power + 4n to the 2nd power +8n -16
10/(20-15)=2 hours
20*2=40 miles
15*2+10=40 miles
Glen catch up with Maria after 2 hours at 40 miles
Answer:
14
Step-by-step explanation:
We solve this by using 2 to open the bracket
(3+4)2 is the same as 2(3+4)
2(3)+2(4)
=6+8
=14
OR
(3+4)2 is the same as 2(3+4)
So we can solve the one inside the bracket first
=2(7)=14
3x - 7 + 6 = 7x + 6
First shift all the pure numbers to one side
3x = 7x + 6 + 7 - 6
Now add up the pure numbers
3x = 7x + 7
Shift the 7x to the other side
3x - 7x = 7
-4x = 7
Divide 7 by - 4
X = - 1.75