Question 1054483
Original Box:
3, 5, 8
volume, {{{3*5*8}}}


New Box:
(3+x), (5+x), 8
NewVolume, {{{(x+3)(x+5)*8}}}


New Box volume increase by 34 cubic cm's:
{{{highlight_green(8(x+3)(x+5)-8*3*5=34)}}}
Can you do the rest from here?