1.

which is further simplified to

which is 20.
2.
Well,
First solve the square root which is 7
Funny enough, this makes 7 * 7 = 49
So the answer is 49!
Hope I helped!
Answer:
Step-by-step explanation:
There is no precipitate. NaBr is very soluble.
It is not a double replacement. There is only 1 product. Double replacements have two.
It is not a decomposition. If this equation was written backwards, the reaction would be a decomposition.
It must be a synthesis.
Step-by-step explanation:
The coefficients of the y terms are -3 and 2. The least common multiple of 3 and 2 is 6. So multiply the first equation by 2 and the second equation by 3, so that the y terms have a coefficient of 6.
4x − 6y = 42
-18x + 6y = 21
The signs are opposite, so add the equations together.
-14x = 63
x = -9/2