Answer:
16b4=9
Step-by-step explanation:
(4b²+3) (4b²-3)
16b4-12b²+12b²-9
16b(raised to power 4)-9
16b4-9
collect like terms
82
284mm²
S.A.= 2(lw) + 2(lh)+ 2(wh)
2[12.6(8)] + 2[12.6(2)] + 2[8(2)]
201.6 + 50.4 + 32
S.A.= 284mm²
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