Cammy bought a jacket at $43.50. The price was 25% off the regular price.
What was the regular price?

well, the regular price was "x" and that's namely the 100%.

however today's price is 43.50, and we know that's 25% off the regular "x" price , hmmm so 100% - 25% = 75%, so 43.50 is really 75% of the regular price, so

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116