Respuesta :
Hope This Helped!
Step-by-step explanation:
First off we need to take the whole equation and multiply it so that we can get rid of the fractioned exponent. The number we would use is 12, giving us the new equation: a + 252 = 300. We then can subtract 252 from both sides of the equation, to get the exponent by itself and intentionally create an answer. This would be: a + 252 = 300,-252=48 or a = 48
We are left with A being equal to 48.
[tex]\dfrac 1{12} \cdot a +21 = 25\\\\\\\implies \dfrac a{12} = 25-21\\\\\\\implies \dfrac a{12} =4 \\\\\\\implies a = (12)(4) = 48[/tex]