It is given that the circumference of the circle is 19.5 inches. Let the diameter is d inches .
And the formula of circumference is
Substituting the value of C, we will get
When the diameter increased by 3, then the circumference is
And the circumference , when diameter is increased by 3 is 29 inches .
Answer:
9 is the right answer
Step-by-step explanation:
I. If c = - 4 and d = 10
then 
= 
= 
= 9
Hope that help :D
First set everything to 0.
Giving you A= 1 , B= 1 and C= -5
Then input everything into the quadratic formula and either solve by hand or use a calculator.
Note exact values are found by hand, decimals are found using a calculator.
So an additional discount of 50% off the sale price would bringthe price to 35% (that is, 50% • 70%) of the original price. Thus, a $100item would cost $35 after both discounts. An 80% off sale means thatyou pay 100% – 80%, or 20% of the original cost of the item.
Answer:
Bobby around 131 minutes and Billy around 111 minutes
Step-by-step explanation:
To solve the problem it is important to raise equations regarding what happens.
They tell us that Billy (Bi) and Bobby (Bo) can mow the lawn in 60 minutes. That is to say that what they prune in a minute is giving as follows:
1 / Bo + 1 / Bi = 1/60 (1)
They say Billy could mow the lawn only in 20 minutes less than it would take Bobby, therefore
1 / Bi = 1 / (Bo-20) (2)
Replacing (2) in (1) we have:
1 / Bo + 1 / (Bo-20) = 1/60
Resolving
(Bo - 20 + B0) / (Bo * (Bo-20) = 1/60
120 * Bo - 1200 = Bo ^ 2 - 20Bo
Rearranging:
Bo ^ 2 - 140Bo -1200 = 0
Now applying the general equation
Bo = 130.82 or Bo = 9.17, <em>this last value cannot be because Billy took 20 minutes less and neither can he prune faster than the two together</em>, therefore Bobby only takes around 131 minutes and Billy around 111 minutes
Checking with equation 1:
1/131 +1/111 = ~ 1/60
