Answer:
x = 12
Step-by-step explanation:
<u>To find "x"</u>, we need to <u>isolate it</u>. This means move "x" to the left side, and everything else to the right side.
When moving a number, do its <u>reverse operation</u> to the entire equation.
x + 9 = 2x - 3
x - 2x + 9 = 2x - 2x - 3 Subtract 2x from both sides
-x + 9 = -3
-x + 9 - 9 = -3 - 9 Subtract 9 from both sides
-x = -12
-x/-1 = -12/-1 Divide both sides by -1 to get rid of the negatives
x = 12 Final answer
Check your answer. Split the equation for the left and right sides. Substitute "x" for the answer "12".
LS: (left side)
x + 9
= 12 + 9 Add
= 21
RS: (right side)
2x - 3
= 2(12) - 3 Multiply before subtracting
= 24 - 3 Subtract
= 21
Both sides equal to 21 when "x" is 12.
LS = RS left side equals right side
Therefore the answer is correct.