Answer:
The original dimensions of the garden are
Length [tex]8\ ft[/tex]
Width [tex]5\ ft[/tex]
Step-by-step explanation:
Let
x-----> the original length of the garden
y-----> the original width of the garden
we know that
[tex]x=y+3[/tex] -----> equation A
The original area is equal to
[tex]A=xy[/tex]
substitute equation A
[tex]A=(y+3)y\\A=y^{2}+3y[/tex]
if he increases the length by 4 feet and decreases the width by 1 feet, he will gain 8ft^2 in area
so
The new area is equal to
[tex]An=(x+4)(y-1)[/tex]
substitute equation A
[tex]An=(y+3+4)(y-1)\\An=y^{2}-y+7y-7\\An=y^{2}+6y-7[/tex]
Remember that
[tex]An=A+8[/tex]
substitute the values
[tex]y^{2}+6y-7=y^{2}+3y+8[/tex]
[tex]6y-3y=8+7[/tex]
[tex]3y=15[/tex]
[tex]y=5\ ft[/tex]
find the value of x
[tex]x=5+3=8\ ft[/tex]
therefore
The original dimensions of the garden are
Length [tex]8\ ft[/tex]
Width [tex]5\ ft[/tex]