Answer:
[tex]7a^{2} +20[/tex]
Step-by-step explanation:
Given: Area of one cupboard= [tex]3a^{2} -5y+15[/tex]
Area of second cupboard= [tex]4a^{2} +5y+5[/tex]
As per question, carpenter need to determine the amount of plywood required for two cupboard.
Lets, add the area of two cupboard to know the amount of plywood required.
∴ [tex]3a^{2} -5y+15[/tex]- Area of first cupboard.
[tex]4a^{2} +5y+5[/tex]- Area of second cupboard.
Adding both the area;
[tex](3a^{2} -5y+15)+(4a^{2} +5y+5)[/tex]
Now, opening the parenthesis
[tex]3a^{2} -5y+15+4a^{2} +5y+5[/tex]
we will get [tex]7a^{2} +20[/tex].
∴ Total area of cupboard= [tex]7a^{2} +20[/tex]
