The length and breadth of a rectangle are (4×+7)cm and (5x-4)cm respectively. If the area of rectangle is 209 cm, 1)find the Value of x 2) the perimeter of the rectangle

Question

Quadratic equations and graphs

Answer 1

(4x+7)(5x-4) = 209

20x^2 + 19x - 28 = 209

20x^2 + 19x - 237 = 0

( x - 3 )(20x + 79 ) = 0

20x+79 results in negative measures

x-3=0 --> x =3

4(3) + 7 = 12 + 7 = 19

5(3) - 4 = 15 - 4 = 11

The area is 209

The perimeter is 60