Question

If xy = -6 , what is the value of xy(x+y ) ? (1) x – y = 5 (2)

Answer 1

x - y = -1

x + y = 9

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2x = 8

Divide both sides by 4 giving:

x = 4

Solve for y:

Substitute for x in the second equation to find the value for y.

4 + y = 9

Subtract 4 from both sides of the equation gives:

y = 5

Solution: x = 4, y = 5

Check:

substitute for x and y in first equation:

4 - 5 = -1

-1 = -1, values check.