Answer:
Just by simply adding the two quantities you can get the net change. $67.12 +(addition sign because we want the net change) $2.56= $69.68. The last number is the net change!
Step-by-step explanation:
#9) b^4 - 81 = (b^2)^2 - 9^2 = (b^2+ 9)(b^2- 9)<span>
#5) m^4-1 = (m^2)^2 - 1 = </span>(m^2 + 1)(m^2- 1)<span>
#10) 81x^4-16 = (9x^2)^2 - 4^2
= (9x^2 +4)(9x^2 - 4)
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