Question

When the length of rectangle is decreased by 10 ft and the breadth is increased by 5ft the rectangle becomes a square and its area is reduced by 210 sq ft?

Answer 1

Answer:

Step-by-step explanation:

let the actual length be L and actual breadth b B

so new length = L - 10

new breadth = B + 5

 area of rectangle equal to = l x b = (L-10)(B+5) {new area}

   LB - 210 = (L-10)(B+5)   {area reduced by 210}   - EQ1

rectangle becomes square so

L-10 = B + 5 {sides equal}

L-B = 15

L = B +15 - EQ2

SUBSTITUTE EQ 2 IN EQ 1

LB - 210 = (L-10)(B+5)

B X B + 15 - 210 = (B+15-10)(B+5)

B^2 + 15B -210 = B^2 + 25 + 10B

15B - 210 = 25 + 10B  {B^2 gets cancelled}

5B = 235

B = 47ft

substitute the value nd get value of length