Answer:
Step-by-step explanation:
y=x+7.........(1)
y=3x+5.......(2)
Equating the two equations
3x +5 = x + 7
3x -x = 7 - 5
2x = 2
x = 2/2
x = 1
Putting x = 1 in (1)
y = x + 7
y = 1 + 7
y = 8
Answer:
We know that 30/25 is 1.2 or 1 1/5. SO if we divide 20 by that then we'll get 16.6667. So I won't give you the answer because its best that you learn to do this yourself because its more beneficial than telling you. What you have left is 16.6667=4x-4. Combine like terms and you'll get your answer. But if your still stuck then you can just let me know and I'll help you as much as I can.
Make x the subject means you need to solve for x
y = ax^2 solve for x
divide both side by a
y/a = ax^2/a
simplify
y/a = x^2
so
x = square root (y/a)
Let s = the speed of the slower train in km/hrs+10 = the speed of the faster train in km/hrLet t = time in hrs for the slower train to go 160 kmt-5 = time in hrs for faster train to go 160 km---------------Slower train:(1)
160=s.t
Faster train:(2) 160=(s+10) .(t-.5)From (1)(1) t=160/s
use the relations given in following screenshot and then use quadratic equation.
the discriminant b^2 - 4ac when the equation is in the form of ax^2 +bx+c=0
13x^2-16x = x^2 -x
we need to get in it the standard form
subtract x^2 from each side
12x^2 -16x = -x
add x to each side
12x^2 -15x = 0
12x^2 -15x -0 =0
a=12 b=-15 c=0
b^2 -4ac
the discriminant = b^2
b^2 = (-15)2 = 225