Method 1:
[tex]\begin{array}{cccc}25\%&-&80&|:5\\5\%&-&16&|\cdot18\\90\%&-&288\end{array}\\\\Answer:\ 90\%\ of\ x\ is\ equal\ 288[/tex]
Method 2:
[tex]\begin{array}{ccc}25\%&-&80\\90\%&-&a\end{array}\ \ \ |\text{cross multiply}\\\\25a=90\cdot80\ \ \ |:25\\\\a=\dfrac{7200}{25}\\\\a=288\\\\Answer:\ 288[/tex]
