Respuesta :
Answer:
52.
Step-by-step explanation:
Let x be the number of total pies before the bake sale started.
We have been given that at the beginning of the bake sale, Mary set aside 2 pies for herself.
So the pie left for sale will be x-2.
We are also told that Karen bought half of the remaining pies for her birthday party, so number of pies bought by Karen will be: [tex]\frac{x-2}{2}[/tex].
Further, we are told that 10 more pies were sold during the sale, so number of total pies sold and used by Mary will be:
[tex]2+\frac{x-2}{2}+10[/tex]
As there were 15 pies remaining, so we can represent total number of pies in an equation as:
[tex]x=2+\frac{x-2}{2}+10+15[/tex]
[tex]x=\frac{x-2}{2}+27[/tex]
Let us have a common denominator.
[tex]x=\frac{x-2}{2}+\frac{27*2}{2}[/tex]
[tex]x=\frac{x-2}{2}+\frac{54}{2}[/tex]
[tex]x=\frac{x-2+54}{2}[/tex]
[tex]x=\frac{x+52}{2}[/tex]
Let us multiply both sides of our equation by 2.
[tex]2x=\frac{x+52}{2}*2[/tex]
[tex]2x=x+52[/tex]
[tex]2x-x=x-x+52[/tex]
[tex]x=52[/tex]
Therefore, there were 52 pies before the bake sale started.
