First, we must understand why the three other choices are not mixtures. Salt is a compound made from elements Sodium and Chlorine. Aluminum is an element. Carbon dioxide is also a compound composed of Carbon and Oxygen.
Now, gasoline. is substance made from refined crude oils (or hydrocarbons). As a matter of fact, gasoline is an example of a homogenous mixture.
Thus, amongst the choices, the mixture would be gasoline<span>.
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Your answer is xy-1<span><span>
</span></span><span>=<span><span><span><span>4<span>x2</span></span><span>y2</span></span>−<span><span>4x</span>y/</span></span><span><span>4x</span>y
</span></span></span><span>=<span><span><span><span>4x</span>y</span>−4/</span>4
</span></span><span>=<span><span>xy</span>−<span>1
</span></span></span>Hope this helps!
1 can go into anything so that is the mystery number sorry if not right first time on here