Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS. Note that PEMDAS =
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
& is the order of operation.
Also note, that you are solving for x, in all instances.
1) x + c = d
Note the equal sign, subtract c from both sides:
x + c (-c) = d (-c)
x = d - c
2) x - p = g
Note the equal sign, add p to both sides:
x - p (+p) = g (+p)
x = g + p
3) FX = S
Note the equal sign, divide F from both sides:
(FX)/F = (S)/F
X = S/F
4) 3x - q = p
Note the equal sign, first, add q to both sides:
3x - q (+q) = p (+q)
3x = p + q
Next, divide 3 from both sides. Note that when you divide 3 from the right side, you are dividing from all terms:
(3x)/3 = (p + q)/3
x = (p + q)/3
5) cx - d = 4
Note the equal sign, first, add d to both sides:
cx - d (+d) = 4 (+d)
cx = 4 + d
Next, divide c from both sides.
(cx)/c = (4 + d)/c
x = (d + 4)/c
6) FX - S = M
Isolate the variable, x. First, add S to both sides:
FX - S (+S) = M (+S)
FX = M + S
Next, divide F from both sides:
(FX)/F = (M + S)/F
X = (M + S)/F
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