Line a and b are perpendicular
answer : option C

Lets find the number of zeros by factoring

Group first two terms and last two terms

Factor out GCF from each group


Now we set each factor =0 and solve for x
0 = (x^2-8) and (x + 1)=0
and x = -1
and x= -1
So we have three real zeros
The function has three real zeros. The graph of the function intersects the x-axis at exactly three locations.
We know that:
<span>rate = 0.15 heaters /labor hour</span>
labourer time = 160 hours /
month
goal = 57,600 heaters / year
We can solve this problem by
simply looking at which ratios will cancel out the units:
<span>number of labourers = (57,600
heaters/year) / [(0.15 heaters /labor hour) * (160 hours/month) * (12 month/year)</span>
<span>number of labourers = 200</span>