Answer:
387 contains 80 and 8 x 10 = 80
(x-1)(x-9)
Hope this helps
Suppose the larger pump alone can empty the tank in L hours, and the smaller pump can finish the job in S hours, then each hour the large pump empties 1/L portion of the tank, and the small pump empties 1/S per hour
Working together for three hours, they empty the whole tank, which is 100% of it, so 3/L+3/S=100%=1
Larger pump can empty the tank in 4 hours less than the smaller one, so L=S-4
replace L: 3/(S-4)+3/S=1
Make the denominator the same to solve for:
3S/[S(S-4)] +3(S-4)/[S(S-4)]=1
(3S+3S-12)/[S(S-4)]=1
(3S+3S-12)=[S(S-4)]
S^2-10s+12=0
use the quadratic formula to solve for S
S is about 8.6
The answer is not whole hour.
The number of patches that Leia can cut from 32 pieces of the fabric measuring 18 cm by 10 cm will be as follows:
Number of pieces=[total area of fabric]/[area of patch]
area of fabric=18×10=180 cm²
Area of 32 patches=180×32=5760 cm²
Area of patch=45 cm²
Number of patches=5760/45=128 patches
I believe it's the 3rd one