Answer: 16 litres
Step-by-step explanation:
A: 1l x km
B: 1l x+5 km
Running 400 km A used 400/x litres
Running 400 km B used 400/(x+5) litres
400/x- 400/(x+5)= 4
400*(x+5)- x*400-4*x*(x+5)=0
400*x+2000-400*x-4*x²-20*x=0
2000-4*x²-20*x=0 difide by 4 both sides of equation
500-x²-5*x=0
Lets solve the equation using discriminant:
D=5²-(-1)*4*500=2025
sqrt(D)=45
x1= (5+45)/(-2)= -25 x2=(5-45)/(-2)=20
x1=-25 x2=20
x1<0 so is not the solution of the problem ( number of litres can't be negative)
So A uses litr per x=20 km and B uses 1 litr per 20+5=25 km
Running 400 km B uses 400/25=16 litres
Hey there! I'm happy to help!
We want to get c all by itself on one side of the equation. Usually variables go on the left side, so let's flip the equation around.
c/9=-8
If we multiply c/9 by 9, the 9 will cancel out because if you divide by 9 and then multiply by 9 it just equals 1. We can do this to isolate the c, but whatever you do to one side of the equation, you have to do to the other. So, we multiply both sides by 9.
c/9×9=-8×9
c=-72
Have a wonderful day! :D
Answer - 5
Explanation - answer is not 13...
4 + ___ = 9
So now you should 9 - 4 = 5
so answer is 5.....
I hope you Understand...
all we can really cancel is one of the (x-5) and the "x", is all.
