D.(m-6)(m-8) is the answer
∛(1/8 - <em>x</em>) = -1/2
Take the 3rd power of both sides and solve:
(∛(1/8 - <em>x</em>))³ = (-1/2)³
1/8 - <em>x</em> = -1/8
2/8 = <em>x</em>
<em>x</em> = 1/4
42/12 = 3.5, 63/18 = 3.5, therefore we will be multiplying the last time by 3.5. 40x3.5= 140, and therefore, the number of pencils produced in 40 seconds is 140
113.5+22.41 = 135.91 if that’s what’s your asking :)