Answer:


Step-by-step explanation:
Given



Required
Find P(A) and P(B)
We have that:
--- (1)
and
--- (2)
The equations become:
--- (1)

Collect like terms


Make P(A) the subject

--- (2)


Substitute: 
![[0.770 - P(B)] * P(B) = 0.144](https://tex.z-dn.net/?f=%5B0.770%20-%20P%28B%29%5D%20%2A%20P%28B%29%20%3D%200.144)
Open bracket

Represent P(B) with x

Rewrite as:

Expand

Factorize:
![x[x - 0.45] - 0.32[x - 0.45]= 0](https://tex.z-dn.net/?f=x%5Bx%20-%200.45%5D%20-%200.32%5Bx%20-%200.45%5D%3D%200)
Factor out x - 0.45
![[x - 0.32][x - 0.45]= 0](https://tex.z-dn.net/?f=%5Bx%20-%200.32%5D%5Bx%20-%200.45%5D%3D%200)
Split

Solve for x

Recall that:

So, we have:

Recall that:

So, we have:


Since:

Then:


Answer:
John and Mike are correct, Henry is incorrect.
Step-by-step explanation:
Try to find x = 4 for all the equations to find out who is correct.
John:
4x + 4 + 7x = 48
Combine like terms.
11x + 4 = 48
Subtract 4 from both sides.
11x = 44
Divide both sides by 11.
x = 4
John is correct.
Mike:
2x + 3 = 11
Subtract 3 from both sides.
2x = 8
Divide both sides by 2.
x = 4
Mike is correct.
Henry:
8x + 7 = 71
Subtract 7 from both sides.
8x = 64
Divide both sides by 8.
x = 8
Henry is incorrect.
1/8 + c = 4/5
c = 4/5 - 1/8
c = 32/40 - 5/40
c = 27/40