Answer:
Equations: 
number of chickens = 52
number of goats = 28
Step-by-step explanation:
Given: A small ranch has chickens and goats
Total number of heads = 80
Total number of legs = 216
To find: number of chickens and goats
To draw: the graph
Solution:
Let x denotes number of chickens and y denotes number of goats.
According to the question,

From (i), put
in (ii)

Put
in equation (i)

So,
number of chickens = 52
number of goats = 28
Answer:
-7
Step-by-step explanation:
You have to add water and syrup and then change the unit to liters. 1000ml is 1l.
It looks like you might have intended to say the roots are 7 + i and 5 - i, judging by the extra space between 7 and i.
The simplest polynomial with these characteristics would be

but seeing as each of the options appears to be a quartic polynomial, I suspect f(x) is also supposed to have only real coefficients. In that case, we need to pair up any complex root with its conjugate to "complete" f(x). We end up with

which appears to most closely resemble the third option. Upon expanding, we see f(x) does indeed have real coefficients:

The bicycle with a 30-inches diameter rolls approximately 28.8 more than a tire with the diameter with 21-inches.
<u><em>How to solve:</em></u>
- First use the formula: C = 3.14d
- Replace the d value with 30 and solve the equation:
C = 3.14 x 30 ⇒ 94.2477796077
- Then solve the equation again but 21 as the d value:
C = 3.14 x 21 ⇒ 65.9734457254
- Then subtract 65.9734457254 from 94.2477796077 to get the approx. answer of 28.8