Remember to follow the order of operation, PEMDAS. PEMDAS stands for:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
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5. 9(7x - 4) = 27
First, distribute 9 to all terms within the parenthesis:
9(7x - 4) = 27
(9 * 7x) - (9 * 4) = 27
63x - 36 = 27
Next, isolate the variable, x. Do the opposite of PEMDAS.
First, add 36 to both sides:
63x - 36 (+36) = 27 (+36)
63x = 27 + 36
63x = 63
Isolate the variable, x. Divide 63 from both sides:
(63x)/63 = (63)/63
x = 63/63 = 1
x = 1
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6. 5(3x + 8) = 175
First, distribute 5 to all terms within the parenthesis:
5(3x + 8) = (5 * 3x) + (5 * 8) = 15x + 40
15x + 40 = 175
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 40 from both sides:
15x + 40 (-40) = 175 (-40)
15x = 175 - 40
15x = 135
Next, divide 15 from both sides of the equation:
(15x)/15 = (135)/15
x = 135/15 = 9
x = 9
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