Solution :
Let A = Economics, B = Mathematics
n(A) = 311, n(B) = 243, 
a). So, 
= 311 + 243 - 135
= 419
b). n(A only) = 311 - 135
= 176
n(B only) = 243 - 135
= 108
Exactly one of these two courses

= 0.568
c). Neither economics nor mathematics


= 0.162
Answer:
The answer would be (1.23, 4.39)
Step-by-step explanation:
Because they are both equal to y, we can set the equations equal to each other and then solve.
4.9x - 1.64 = -0.25x + 4.7
5.15x - 1.64 = 4.7
5.15x = 6.34
x = 1.23
Now that we have the value for x, we can plug into either equation and find y.
y = -0.25x + 4.7
y = -0.25(1.23) + 4.7
y = -.31 + 4.7
y = 4.39
1. False
2. True
3. False
4. False??
The second choice
7+ -13= -6