Answer: 12 in. by 10 in.
Step-by-step explanation:
Given: The dimensions of photo is 10 in. by 8 in.
Therefore, Area of photo= [tex]10\times8=80\ in.^2[/tex]
Area of frame with photo=120 square inches
Let x be the width of the frame, then we have
Length of frame with photo= 10+2x inches
Width of frame with photo =8+2x inches
Now, [tex](10+2x)(8+2x)=120[/tex]
[tex]80+16x+20x+4x^2=120\\\Rightarrow\ 4x^2+36x-40=0\\\Rightarrowx^2+9x-10=0\\\(x-1)(x+10)=0\\\Rightarrow\ x=1,...........[text{Since length can not be negative so it cannot be -10}][/tex]
Thus, dimension of frame = [tex](10+2(1))(8+2(1))=12\ in.\ by\ 10\ in.[/tex]