Answer:
D
Step-by-step explanation:
total marbles
9
red marbles- 4
so prob is 4/9 or D
if my answer helps please mark as brainliest
Given:
A man walks for x hours at a speed of (x + 1) km/h and cycles for (x - 1) hours at a speed of (2x + 5) km/h.
Total distance travelled is 90 km.
To find:
The value of x.
Solution:
We know that,


A man walks for x hours at a speed of (x + 1) km/h, so walking distance is
km
The man cycles for (x - 1) hours at a speed of (2x + 5) km/h, so the cycling distance is
km
Now,
Total distance = 90 km









Time cannot be negative. So, the only possible value of x is 5.
If the discriminant is negative no real solution exists.
If the discriminant is equal to 0 only one real solution exists.
If the discriminant is positive 2 real solutions exist.
The discriminant:
D = b² - 4 a c
1 ) - 7 x² + 6 x + 3 = 0
D = 6² - 4 · ( - 7 ) · 3 = 36 + 84 = 120 > 0
Answer: b) two solutions
2 ) - 8 x² - 8 x - 2 = 0
D = ( - 8 )² - 4 · ( - 8 ) · ( - 2 ) = 64 - 64 = 0
Answer: a ) one solution
Answer:
.5
Step-by-step explanation:
3/4 of a mi is equal to 0.75 mi
2/3 of .75 is .5