12. ∆ABD is similar to ∆PQD, so
QD/z = BD/x
Likewise ∆CDB is similar to ∆PQB, so
QB/z = BD/y
Since QD + QB = BD, you have
QD/z + QB/z = BD/x + BD/y
BD/z = BD/x + BD/y
Dividing by BD gives the desired result:
1/x + 1/y = 1/z
13. Triangles ABD, BCD, and ACB are all similar. This means
AB/AC = AD/AB
AB² = AC×AD = (4 cm)×(9 cm)
AB² = 36 cm²
AB = 6 cm
and
BD/CD = AD/BD
BD² = CD×AD = (5 cm)×(4 cm)
BD² = 20 cm²
BD = 2√5 cm
Answer:
change: $7.78
Step-by-step explanation:
The change would be $20 - ($1.88/lb)(6.5 lb) = $7.78
Answer: 67
Step-by-step explanation:
Let x = number of passengers.
Case M: x< =75 (no refund)
Cost per passenger = $230
To generate the revenue, we should satisfy
230x =15990
x = 69.5
Set x = 67 in order to generate the revenue.
Case N: x>75
Cost per passenger minus refund = 230 - 5 = $225
Therefore
225x = 15990
x = 71.1
Because x<75, ignore this answer.
More than 75 passengers will generate more than $15990.
Answer:
One.
Step-by-step explanation: