Question 1209915
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I'll highlight <font color=blue>5x+3y = 3</font> in blue to indicate it's useful for a substitution step later on.


1024^x*64^y
= (2^10)^x*(2^6)^y
= 2^(10x)*2^(6y)
= 2^(10x+6y)
= 2^(2(<font color=blue>5x+3y</font>))
= 2^(2(<font color=blue>3</font>)) ...... <font color=blue>substitution</font>
= 2^(6)
= <font color=red>64</font>


Therefore,
1024^x*64^y = <font color=red>64</font> when 5x+3y = 3
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