Answer:
a = 2x - b
Step-by-step explanation:
[tex]x = \frac{a + b}{2}[/tex]
Use the reciprocal of 1/2 to get rid of the fraction by multiplying both sides of the equation by 2/1:
[tex](\frac{2}{1})x = \frac{a + b}{2} (\frac{2}{1})[/tex]
2x = a + b
finally, subtract b from both sides of the equation to isolate a:
2x - b = a + b - b
2x - b = a