C. Island
i need 20 characters
Answer:
9 (1-2x²)
Explanation:
The given expression is:
30 - 9x²*2 - 21 - 4 + 4
The first step is to compute the multiplication. This will give:
30 - 18x² - 21 - 4 + 4
Then, we will add like terms as follows:
(30-21-4+4) - 18x²
= 9 - 18x²
Finally, we can take the 9 as a common factor from both terms, this will give:
9 (1-2x²)
Hope this helps :)
Answer:
NaBr
Explanation:
When AgBr is dissolved in water, the following equilibrium is set up in solution;
AgBr(s)⇄Ag^+(aq) + Br^- (aq)
If we dissolve NaBr in the water, a common ion (Br^-) is now introduced into the system. This increases the concentration of Br^- and favours the reverse reaction hence more AgBr is precipitated. This is known as common ion effect.
Because teachers don’t really understand it all that well themselves so they can’t teach it effectively
