<pre><code> If 2^x + 2^x + 2^x + 2^x = 2^7, what is the value of x?
<p>What I did was 2^4x = 2^7, but that is wrong, and it's supposed to be 4 * 2x, but I don't understand the exponent rule for this. Could someone please explain it to me?</p>
<pre><code> If x and y are positive integers and 4(2^x) = 2^y, what is x in terms of y?
<p>A. y - 2
B. y - 1
D. y + 1
E. y + 2</p>
<p>Is it possible for me to multiply the 4(2^x) by doing 8^x? Or can I not do that because the 4 does not have an exponent? Could someone, again, please help me to understand the rule behind this?</p>