The answer is 10 pairs of shoes.
The first ratio is 10:5. 10 socks per 5 pairs of shoes. You have 20 socks now instead of 10. You just double the ratio. 20 socks per 10 pairs of shoes. 20:10.
See attached photo for answers. let me know if you are doing rounding to a specific decimal.
180 minus 90 equals 90, divided by 2, the answer is 45 degrees
You solve the equation : t^2 - 9t - 90 = 0 ;
Δ = ( - 9 )^2 - 4 * 1 * ( - 90 ) = 81 + 360 = 441 ;
t1 = ( 9 +

) / 2 = 30 / 2 = 15 ;
t2 = ( 9 -

) / 2 = -12 / 2 = - 6 ;
The numbers are 15 and - 6 ;
Answer:
257.5 mph
332.5 mph
Step-by-step explanation:
The initial distance between the two planes is 960 miles, while the final distance (after t=1.5 h) is 75 miles, so the total distance covered by the two planes in 1.5h is
miles
Calling v1 and v2 the velocities of the two planes, we have the following equations:
(1)
--> velocity of plane 1 exceeds velocity of plane 2 by 75 mph
(2)
--> the total distance covered by the two planes is 885 miles (t=1.5 h is the time, and the products v1 t and v2 t represent the distance covered by each plane)
Substituting t=1.5 h, the second equation becomes:

By substituting (1) into this last equation, we find:

And substituting this back into eq.(1), we find

So, the speeds of the two planes are
257.5 mph
332.5 mph