Question

Simplify :
2xy (x – 4) + 5y and find its value for
(1) x = 2, y = -1 (ii) x=1/4, y=-1/2
​

Answer 1

Answer:

Step-by-step explanation:

2xy (x – 4) + 5y

1) -  x = 2, y = -1 then

2 X 2 X ( -1 ) ( 2 - 4 ) + 5 X ( -1 )

- 4 ( 2 - 4 ) - 5

- 8  + 16 - 5

-13 + 16

3

2) - x = 1/4, y = - 1/2 then

2 X 1/4 X ( -1/2 ) ( 1/4 + 1/2 ) + 5 X ( -1/2 )

- 2/ 8 ( 1/4 + 2/4 ) - 5/2

-2/8 x 1/4 - 2/8 x 2/4 - 5/2

- 1/ 16 - 1/8 - 5/2

- 1/ 16 - 2/16 - 40/16

( -1 - 2 - 40 ) / 16

- 43 / 16