Answer:
25
Step-by-step explanation:
Number of rows: x
Number of trees per row: y
So x rows multiplied by y trees per row = 700
x × y = 700
xy = 700
This is our first equation
x rows = y trees per row plus three (or x rows minus three = y trees)
x = y + 3
So if x = y + 3,
In xy = 700, we can substitute the x because we have it's value
(y + 3)y = 700
y² + 3y = 700
Divide 3 by 2 then square the answer = 2.25
y² + 3y + 2.25 = 700 + 2.25
Simplify
(y + 1.5)² = 702.25
Get the square root of both sides
(y + 1.5) = ±26.5
y = 26.5 - 1.5 or -26.5 - 1.5
So y is either 25 or -28 (A negative number of trees doesn't make sense so we'll stick with 25
