Answer: 4.2 yards
Step-by-step explanation:
Let x = length of the Flores' lawn in yards.
Then, Area of lawn = 4x sq. yard [Area of rectangle = width x length , here width = 4 yds (given)]
Charge per square yard = $1.25
Charge for Flores lawn = 1.25 × (Area of lawn)
= 1.25 (4x)
= 5x
As per given,
[tex]5x=21\\\\\Rightarrow\ x=\dfrac{21}{5}\\\\\Rightarrow\ x=4.2[/tex]
Hence, the length of the Flores's lawn = 4.2 yards