Question 891971
A rectangular hall has"m" rows and (36-m) columns of seats. If the number of seats of the hall exceeds 320.
Find the value for m  to equal 320
m(36-m) = 320
-m^2 + 36m - 320 = 0
multiply by -1
m^2 - 36m + 320 = 0
Factors to (m-16)(m-20)
m = 16
and
m = 20
:
Graphically, green is 320
{{{ graph( 300, 200, -6, 40, -50, 400, x*(36-x), 320) }}}
:
A. Find all the possible values of "m"
m = 17, 18, 19, to exceed 320 seats
:
B. Find the max. # of seats in the hall
max occurs when m = 18
18(36-18) = 324 seats