WAEC - Mathematics (1999 - No. 3)
If \(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\), find K.
-2
-1
1
2
Обяснение
\(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\\
2K\sqrt{7}+3\sqrt{7}-\sqrt{7}=0\\
2K\sqrt{7}=-2\sqrt{7}\\
K=\frac{-2\sqrt{7}}{2\sqrt{7}}\\
K=-1\)
\(K\sqrt{28}+\sqrt{63}-\sqrt{7}=0\\
2K\sqrt{7}+3\sqrt{7}-\sqrt{7}=0\\
2K\sqrt{7}=-2\sqrt{7}\\
K=\frac{-2\sqrt{7}}{2\sqrt{7}}\\
K=-1\)