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.
Answer:
B) 8 and 24.
Step-by-step explanation:
Just by looking at the answer choices, since one number must be three times the other, we can determine that the correct answer is B.
Regardless, let's work this out mathematically. Let the first number be <em>a</em> and the second number be <em>b</em>.
Their difference is 16. Hence:

The first number is three times the second number. So:

Substitute:

Solve for <em>b</em>. Subtract:

And divide both sides by two:

So, the second number is 8.
And since the first number is three times the second, the first number is 24.
Our answer is B as expected.
The total mass, in kilograms, of the nails the carpenter bought is 3.9 kilogram
<h3><u>Solution:</u></h3>
Given that carpenter bought 750 nails
Each nail has a mass of
kilogram
To find: total mass, in kilograms of the nails bought
The total mass of the nails bought can be found out by multiplying number of nails bought by mass of each nail
Number of nails bought = 750
Mass of each nail =
kilogram
total mass of the nails bought = number of nails bought x mass of each nail


Thus the total mass of nails bought is 3.9 kilogram
Let's say this number is a:
a*(a-9) = 90
a^2-9a-90 = 0
(a-15)(a+6) = 0
a = 15 or a = -6
Therefor a. would be the correct answer :)