The length of a rectangular field is twice its width If x is

The length of a rectangular field is twice its width. If x is the width, write an expression perimeter of the field. a) 2x2 b) 6x c) 4x d) 6x2 7. Solve the system of equation for x and y and find the value x + y: {3x - 2y = 11 x + 4y = -1} a) 0 b) -4 c) -21/2 d) 2

Solution

6) let width of field be x units

Given length is twice the width ==> length = 2x

Periameter of rectangle = 2(length + width) = 2(2x + x)

==> perimeter = 6x (Option B)

7) 3x - 2y = 11 ------ (1)

x + 4y = -1 -------- (2)

2 * (1) + (2) = 6x -4y + x + 4y = 22 -1

==> 7x = 21

==> x = 3

from (2)

3 + 4y = -1

==> 4y = -4

==> y = -1

==> x +y = 3 -1 = 2 (Option D)

8) 2y(3y - 4(y +1))

= 2y(3y -4y +4)

= 2y(-y +4)

= -2y² +8y (Option D)