Answer:
x = 6.75
Explanation:
Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
PEMDAS is the order of operation, and equals:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtract.
First, combine like terms. Like terms by definition is terms that have the same amount of like variables.
7x -4x + 15 = 7x - 18 + 6
(7x - 4x) + 15 = 7x + (-18 + 6)
3x + 15 = 7x + (-12)
3x + 15 = 7x - 12
Next, isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
First, subtract 7x and 15 from both sides:
3x (-7x) + 15 (-15) = 7x (-7x) - 12 (-15)
3x - 7x = -12 - 15
-4x = -27
Then, isolate the variable x. Divide - 4 from both sides:
(-4x)/-4 = (-27)/-4
x = -27/-4 = 27/4 = 6.75
x = 6.75 is your answer.
~