I am going to explain this using the substitution method, considering it appears to be the best in this situation.
We know (from the bottom equation) that y can equal 3x+20. Using this knowledge, we substitute the y in the top equation for 3x+20. Now, we have an equation that looks like this:
3x+20=x^2+2x
Now we need to move x to one side and then do some radicals (square roots).
Subtract the 2x on the right (since it is smaller, negatives = NONONO), which will give you
x+20=x^2
Now, we take the square root of both sides to get
rad(x+20)=x
Now we have to simplify. 20 doesn't have a square root, but 4 goes into 20, and 4 has a square root of 2. This now becomes
2rad(x+5)
This doesn't simplify any further... we have a problem... no way to isolate x as far as my knowledge goes... Sorry, can't help you any further than that, but another person or your teacher might be able to. R.I.P...
Answer:
C. $25
Step-by-step explanation:
We will find,
The slope of the function using 
.
Taking the points (1,40) and (2,55).
Slope = 
i.e. Slope = 
i.e. Slope = 15
Substituting the slope and point (1,40) in the equation 
,
We have, 
i.e. 
i.e. b= 25
Thus, the equation of the linear function is 
.
<em>This linear function represents the cost of the comic book since Lucy purchased it, where x= years.</em>
So, the initial value of the comic book is when x= 0.
So, 
i.e. y= 25
Hence, the cost of the book when Lucy purchased it was $25.
Answer:
$5
Step-by-step explanation:
$5 appeared more in the prices
Answer:
with what......
Step-by-step explanation:
..........
