two trucks start from the same point traveling in different directions. One truck travels at a speed of 54 miles per hour, the other at 48 miles per hour.How long must they travel to be at least 408 miles apart?

解答

tw o t r u c k s s t a r t f ro m t h e s am e p o in t t r a v e l in g in d i ff ere n t d i rec t i o n s . O n e t r u c k t r a v e l s a t a s p ee d o f 54 mi l es p er h o u r, t h e o t h er a t 48 mi l es p er h o u r . Ho w l o n g m u s t t h ey t r a v e l t o b e a t l e a s t 408 mi l es a p a r t ?

time : 4

求解步骤

Translate the problem into an equation:

54 x + 48 x = 408

求解

x, 54 x + 48 x = 408 : x = 4

time : 4