Answer:
C. b²< 40
Step-by-step explanation:
2x²+ bx + 5=0 has no real solutions
=> D< 0
b² < 4ac
b²< 4(2)(5)
b²< 40
For this case we have the following system of equations:

We can write a system of equivalent equations.
For this, it is enough to multiply one of the two equations by a scalar.
Multiplying the equation 1 by 2, we have:

Therefore, the new system of equations is:

Answer:
A system that is equivalent is:
D) 
Answer:
19 keyboards
Step-by-step explanation:
Let d = thumb drives; and k = computer keyboards
Total number of sales of thumb drives and keyboards is 50
50 = d + k
Rearranged:
d = 50 - k
Total revenue from the sale of $24 thumb drives and $49 keyboards is $1675
1675 = 24d + 49k
Sub in d = 50 - k
1675 = 24(50 - k) + 49k
1675 = 1200 - 24k + 49k
475 = 25k
k = 475/25
k = 19
(To check, d = 50 - 19 = 31)
Step-by-step explanation:
Option D is the correct answer because we will cross multiply
4/6 = 9/x
4x = 54
X = 27/2