30% off 25: multiply 25 by .30 to find 30%: 7.5. Now subtract that from the sales price: 25-7.5=17.5
Do the same for store B: .40•30=12. 30-12=18.
So store A is better by $.50 :) hope this helps :)
Answer: 
Step-by-step explanation:
By definition, the sum of the exterior angles of a polygon is 360 degrees.
Knowing this, you can write the following equation:

Then, you must solve for "x" in order to find its value. To do it, you can follow these steps:
1. You need to add the like terms:

2. Now, subtract 40 from both sides of the equation:

3. Finally, you must divide both sides of the equation by 4. Then:

Well, we know that y=1/2x+5 from the first equation. if we substitute that into the second equation, it becomes 2x + 1/2x +5 =1. solve for x. 2x+1/2x= -4, 2 1/2x=-4, x=-1.6. plug that in to one of the equations. 2(-1.6)+y=1, -3.2+y=1, y=-2.2. the solution is (-1.6, -2.2)