Answer:
$33.33 (rounded to nearest cent)
Step-by-step explanation:
12 pizzas --- $20
20 pizzas --- 
× $20 = $33.33 (rounded to nearest cent)
First you multiply both sides by 10, add 40, divide by 4, then square root
10*(4x^2-40/10)= (36)*10
(4x^2-40)+40=(360)+40
(4x^2)/4=(400)/4
x^2=100
x=10
Answer:
Step-by-step explanation:
What we have is a general equation that says this in words:
Laura's hours + Doug's hours = 250 total hours
Since we don't know either person's number of hours, AND since we can only have 1 unknown in a single equation, we need to write Laura's hours in terms of Doug's, or Doug's hours in terms of Laura's. We are told that Doug spent Laura's hours plus another 40 in the lab, so let's call Laura's hours "x". That makes Doug's hours "x + 40". Now we can write our general equation in terms of x:
x + x + 40 = 250 and
2x = 210 so
x = 105
Since Laura is x, she worked 105 hours in the lab and Doug worked 40 hours beyond what Laura worked. Doug worked 145. As long as those 2 numbers add up to 250, we did the job correctly. 105 + 145 = 250? I believe it does!!
13.
(a)
for x = 2:
for x = 5
(b)
The graph is:
(c)
Using the graph:
Using the quadratic formula:
![\begin{gathered} x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ x=\frac{-21\pm\sqrt[]{21^2-4(-5)(-10)}}{2(-5)} \\ x=\frac{-21\pm\sqrt[]{241}}{-10} \\ x=0.54758 \\ or \\ x=3.6524 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20x%3D%5Cfrac%7B-b%5Cpm%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%7D%7B2a%7D%20%5C%5C%20x%3D%5Cfrac%7B-21%5Cpm%5Csqrt%5B%5D%7B21%5E2-4%28-5%29%28-10%29%7D%7D%7B2%28-5%29%7D%20%5C%5C%20x%3D%5Cfrac%7B-21%5Cpm%5Csqrt%5B%5D%7B241%7D%7D%7B-10%7D%20%5C%5C%20x%3D0.54758%20%5C%5C%20or%20%5C%5C%20x%3D3.6524%20%5Cend%7Bgathered%7D)
