(a-b)(a+b) because when you reverse the sum you do axa and ax-b xx
Plane #1 speed: x mph
Plane #2 speed: (x+30) mph
time = time becomes
170 mi 185 mi
---------- = --------------
x x+30
Solving for x, the speed of the slower plane, we get
170x + 5100 = 185 x
5100
Then 15x = 5100, and x = ---------- (mi/hr) = 340 mph
15
The slower plane flies at 340 mph, and the faster one at 370 mph.
Answer: x = 23/6
Step-by-step explanation:
Answer:
x>9
Step-by-step explanation:
-4x + 15 < -21
Subtract 15 from each side
-4x + 15-15 < -21-15
-4x < -36
Divide each side by -4, remembering to flip the inequality
-4x/-4> -36/-4
x >9
