Answer:
3x + 5y = -2 is x=
−5
/3
y+
−2
/3
2x - y = 3 is x=
1
/2
y+
3
/2
Step-by-step explanation:
You can divide it and get 2.2
Answer:
A
Step-by-step explanation:
We know million has 6 zeros.
So, 1 million would be written as:
1,000,000
Similarly, 27 million would be written as:
27,000,000
We know writing a number in scientific notation would make this a decimal in 1 decimal place, so we would select "2.7" as the base of the scientific number.
Now, how many places to the right do we need to go (in 2.7) to make it 27,000,000?
Counting, we see: 7 places
So, power of 10 would be "7", thus we can write:

Answer choice A is right
Writing the equation that governs this situation:
-3C - (2.5C/hr)x = -18C
Simplifying, -3 - 2.5x = -18, or 3 + 2.5x = 18
Combining like terms: 2.5x = 18-3 = 15
Then x = 15/2.5 = 6. The temp. will reach -18C after 6 hours.