Why the output is a zero number ?

see explanation

Step-by-step explanation:

Given

(x - 3) × (x + 4) = 0, that is

(x - 3)(x + 4) = 0

The zero product indicates that (x - 3) = 0 or (x + 4) = 0

x - 3 = 0 ⇒ x = 3

x + 4 = 0 ⇒ x = - 4

Thus if x = 3, then

(3 - 3)(x + 4) = 0 × (x + 4) = 0

Similarly if x = - 4 the output is zero

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet

sorry can't

step-by-step explanation:

i googled though and something came up but it was in science langueage not common english sooo