Before we get started, it is good to remember PEMDAS - the acronym that tells you the order to carry out equations.
P = parentheses
E = exponents
M = multiplication
D = division
A = addition
S = subtraction
Knowing this, we should start by doing the equations <em>within </em>each parentheses.

So we did the addition and subtraction pieces within each group leaving us with the above equation. Now let's multiply:

20 is the answer.
Answer:
A
Step-by-step explanation:
Lets find the values:
<em>Gained</em><em> </em>2.2 kg = 2.2
<em>Lost</em><em> </em>1.5 kg = (-1.5)
<em>Lost</em><em> </em>3.7 kg = (-3.7)
Adding these would be represented by the equation:
2.2 + (-1.5) + (-3.7) = ?
Answer:
n = 0
Step-by-step explanation:
1.2n + 1 = 1 - n
Add n and - 1 on both sides.
1.2n + n = 1 - 1
Combine like terms.
2.2n = 0
Divide both sides by 2.2.
n = 0