WAEC - Mathematics (2006 - No. 32)
Simplify \(\frac{20}{5\sqrt{28} - 2 \sqrt{63}}\)
\(\frac{5\sqrt{7}}{7}\)
\(\frac{5\sqrt{5}}{7}\)
\(\frac{7\sqrt{5}}{7}\)
\(\frac{7\sqrt{7}}{5}\)
Explicació
\(\frac{20}{5 \sqrt{4 \times 7} - 2\sqrt{9 \times 7}}\)
\(\frac{20}{10 \sqrt{7} - 6\sqrt{7}}\)
= \(\frac{20 \sqrt{7}}{4 \sqrt{7}}\)
= \(\frac{5\sqrt{7}}{7}\)
\(\frac{20}{10 \sqrt{7} - 6\sqrt{7}}\)
= \(\frac{20 \sqrt{7}}{4 \sqrt{7}}\)
= \(\frac{5\sqrt{7}}{7}\)