4x-3y=17......(1)
5x+4y=60......(2)
Multiply equation (1) by 4 and equation (2) by 3:-
16x - 12y = 68
15x + 12y = 180
Adding these 2 equations:_
31x = 248
x = 248/31 = 8
Now substitute x = 8 in equation (1):-
4(8) - 3y = 17
32-3y = 17
-3y = -15
y = -15/-3 = 5
So solution is x=8,y=5
Answer:
X = -1
Step-by-step explanation:
6 - 4x = 6x - 8x + 8
-6. -6
-4x = -2x + 2
+2x. +2x
-2x = 2
divide both sides by -2
x = -1
Solutions
1hr = 60 min
180 ÷ 60 = 3
<span>180 min = 3 hrs </span>
Answer: He actually rode 2 miles per hour on his trip
Step-by-step explanation: Maybe unconventional, but express the time it took, then figure the speed.
Time = distance /speed t will represent time, s is the speed: t = 30/s Use the rime it would have taken at the higher speed to create an equation:
t-12 = 30/s+8 replace the y with the 30/s
30/s -12 = 30/s+8
(s)(30/s -12 ) = (s)(30/s+8 ) Cross multiply to cancel denominators
(s-8)(30 -12s) = (s-8)(30s/s+8 ) ==> 30s +240 -12s² -96s =30s Simplify:
(-1)(-12s² -96s +240 ) =0 ==> 12s² +96s -240 divide all by 12
s² + 8s -20 = 0 Factor and solve for s
(s +10)(s -2) =0 s-2=0 S= 2
Proof:
30/2 = 15 hours for original trip at 2mph,
increase speed by 8mph 2 + 8 = 10mph
30 miles at 10mph takes 3 hours; that is 12 hours less than his actual trip.
(Brainilest, please :-)