Answer:
225
Step-by-step explanation:
Mary = 3x (3 times Carey)
Carey = x
Barry = x/2 (Because Carey read twice as many as Barry, it means he read half the amount Carey did)
3x + x + x/2 = 405
4x + x/2 = 405
8x/2 + x/2 (treat these as fractions) = 405
9x/2 = 405
9x = 810 (cross multiply)
x = 90
Mary = 3(90) 270
Carey = 90
Barry = 90/2 45
Mary - Barry
270 - 45 = 225
Hope this helps! :)
Answer:
n=21
Step-by-step explanation:
We must find n.
Remember PEMDAS. First we must do the Parentheses. Lets do distributive property by multiplying a number that is immediately outside the parentheses with each number inside the parentheses. Lets do this one side at a time.
First lets do 5(n - 7). We get 5n - 35
Now 2(n + 14) is 2n + 28
Okay...... now we have 
Now lets do OPPOSITES!!!! We must do the opposite of each thing to both sides.
The opposite of -35 is positive 35. Lets add 35 to both sides. We get:

Now lets do the opposite of 2n which is -2n

this is looking quite nice isnt it..........
The opposite of 3 times n is 3 DIVIDED BY n. So lets divide both sides by 3

amazing.......
Answer:
A=24cm²
Step-by-step explanation:
Area=1/2(product of the diagonals)
A=1/2(6×8)
A=1/2(48)
divide by 2
A=24cm²
Answer:
Index of refraction of transparent is 1.48
Step-by-step explanation:
Snell's law states that;
n1(sinθ1) = n2(sinθ2)
Where;
n1 and n2 represent the indices of refraction for the two media, and θ1 and θ2 are the angles of incidence and refraction that the ray R makes with the normal.
In this question;
n1 = 1;
θ1 = 43.8°
θ2 = 19.3°
n2 is unknown.
Thus using Snell's law, we have;
1 x sin 43.8 = n2 x sin 19.3
n2 = (sin 43.8)/sin 19.3
n2 = 1.48
Answer:
2275
Step-by-step explanation:
9100/4 = 2275
this is why you don't go to college, you get boatloads of debt