Question 256102
{{{4(2^x)+31(2^x)-8=0}}} Start with the given equation.



Let {{{z=2^x}}}



{{{4z+31z-8=0}}} Replace each {{{2^x}}} term with 'z'



{{{35z-8=0}}} Combine like terms.



{{{35z=8}}} Add 8 to both sides.



{{{z=8/35}}} Divide both sides by 35.



{{{2^x=8/35}}} Plug in {{{z=2^x}}}



Recall that {{{b^x=y}}} can be rewritten as {{{log(b,(y))=x}}}



{{{log(2,(8/35))=x}}} Use the property shown above to rewrite the equation.



{{{x=log(2,(8/35))}}} Rearrange the equation.



So the exact answer is {{{x=log(2,(8/35))}}} which approximates to {{{x=-2.12928}}}