(T 4 Marks + C 1 Marks)
Two rectangles contain the same area, 480 square metres. The difference of their length is
10 m and the difference in their widths is 4 m. Find their sides.


Sagot :

Answer:

length= 40cm

width= 120cm

Step-by-step explanation:

Area of a rectangle= lenght× width

Dimensions of 1st rectangle: L,W

Dimensions of 2nd rectangle: L+10; W+4

Hence,

LW = 480__________(1)

(L-10)(W+4) = 480_______(2)

LW = LW+4L - 10W - 40

4L = 10W +40

2L = 5W + 20

L = (5/2)W + 10_________(3)

But LW = 480 (from equation one)

So, W = 480/L

substitute as= 480/L into equation (3)

L = (5/2)(480/L)+10

L = 1200/L + 10

L^2 - 10L - 1200 = 0

factorising.

we're have,

(L-40)(L+30) = 0

therefore, since L can't be negative , L = 40

L = 40 cm (length)

Then 480/L = W = 120 cm (width)

therefore L= 40cm and W= 120cm