Answer:
Original width
=
18
metres
Original length
=
36
mtres
Step-by-step explanation:
The trick with this type of question is to do a quick sketch. That way you can see what is happening and devise a method of solution.
Tony B
Tony B
Known: area is
width
×
length
⇒
600
=
(
w
−
3
)
(
2
w
+
4
)
⇒
600
=
2
w
2
+
4
w
−
6
w
−
12
Subtract 600 from both sides
⇒
2
w
2
−
2
w
−
612
=
0
⇒
(
2
w
−
36
)
(
w
+
17
)
=
0
⇒
w
=
−
17
It is not logical for a length to be negative in this context
so
w
≠
−
17
w
=
18
⇒
L
=
2
×
18
=
36
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Check
(
36
+
4
)
(
18
−
3
)
=
40
×
15
=
600
m
2