Question

Simplify 2xy (x - 4 ) + 5y and itsvalue for x = 2, y= -1​

Answer 1

Answer:

2×2×-1(2-4)+5×-1=-2(-2)+5=4+5=9

Answer 2

Given,

The expression: 2xy (x - 4 ) + 5y.

x = 2 and y = -1

To find,

The value of the given expression.

Solution,

The simplified value of 2xy (x - 4 ) + 5y will be 2x²y-8xy+5y and its value when x = 2 and y = -1 will be 3.

According to the question,

The expression: 2xy (x - 4 ) + 5y.

Multiplying 2xy into the bracket:

2x²y-8xy+5y

Now, putting x = 2 and y = -1:

2(2)²(-1)-8(2)(-1)+5(-1)

2(4)(-1)+16-5

(Note that the product of two negative integers is positive and that of one negative and one positive integer is negative.)

-8+16-5

8-5

3

Hence, the simplified value of 2xy (x - 4 ) + 5y is 2x²y-8xy+5y and its value when x = 2 and y = -1 is 3.