JAMB - Mathematics (2011 - No. 20)
A binary operation \(\oplus\) om real numbers is defined by x \(\oplus\) y = xy + x + y for two real numbers x and y. Find the value of 3 \(\oplus\) - \(\frac{2}{3}\).
- \(\frac{1}{2}\)
\(\frac{1}{3}\)
-1
2
Vysvětlení
N + Y = XY + X + Y
3 + -\(\frac{2}{3}\) = 3(- \(\frac{2}{3}\)) + 3 + (- \(\frac{2}{3}\))
= -2 + 3 -\(\frac{2}{3}\)
= \(\frac{1 - 2}{1 - 3}\)
= \(\frac{1}{3}\)
3 + -\(\frac{2}{3}\) = 3(- \(\frac{2}{3}\)) + 3 + (- \(\frac{2}{3}\))
= -2 + 3 -\(\frac{2}{3}\)
= \(\frac{1 - 2}{1 - 3}\)
= \(\frac{1}{3}\)