Step-by-step explanation:
Remember to isolate the variable for each question. Note the equal sign, what you do to one side, you do to the other.
1) 4 + x = 8
Subtract 4 from both sides
4 (-4) + x = 8 (-4)
x = 8 - 4
x = 4
D) x = 4 is your answer
2) -2x ≤ 6
Note that when dividing or multiplying a negative number, you must flip the sign. Isolate the variable (x).
(-2x)/-2 ≤ (6)/-2
x ≥ 6/-2
x ≥ -3
A & B are the same, so you'll have to ask the teacher which one was supposed to have a negative 3
3) Remember to do the opposite of PEMDAS. First subtract, then multiply. Again, isolate the variable (x).
x/2 + 3 = 5
x/2 + 3 (-3) = 5 (-3)
x/2 = 5 - 3
x/2 = 2
(x/2)(2) = 2(2)
x = 2 * 2
x = 4
A) x = 4 is your answer
4) Remember to do the opposite of PEMDAS. First subtract, then divide. Again, isolate the variable (x).
7x + 6 = 20
7x + 6 (-6) = 20 (-6)
7x = 20 - 6
7x = 14
(7x)/7 = (14)/7
x = 14/7
x = 2
D) x = 2 is your answer
5) You are solving for x. Note that there are two variables, however, you don't need to worry too much about the second variable (a), just know that you cannot combine (using addition or subtraction) a number with variable and a constant (a number without).
First, subtract 8a from both sides:
2x + 8a (-8a) = 10 (-8a)
2x = 10 - 8a
Next, divide 2 from both sides to isolate the variable (x):
(2x)/2 = (10 - 8a)/2
x = (10)/2 (-8a)/2
x = 5 - 4a
D) x = 5 - 4a is your answer
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