The equation -x^2+4x-4=0 has no solutions
a. true
b. false
​

x=2 so it has a solution so it is false

Step-by-step explanation:

true

Step-by-step explanation:

Let us calculate the determinant of this quadratic equation:

Δ = b^2 - 4ac = 16-4*(-1)*(-4) = 0

The equation has one solution

x = -b/2a = 2

80 miles per hour

Step-by-step explanation:

Eric takes a train to his parent’s house 320 miles away.

If the trip takes 4 hours.

A train covers 320 miles in 4 hours.

The unit rate of train is number of miles cover in 1 hour.

Using formula:

where, distance = 320 miles

Time = 4 hours

Hence, The unit rate of train is 80 miles per hour.