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
Answer:
45
Step-by-step explanation:
because the mass
What I would do:
5x + 10y = 35
Divide everything by 5.
x + 2y = 7
x = 7 - 2y
Now plug "x" into either one of the equations.
2(7-2y) + 5y = 15
14 - 4y + 5y = 15
14 + y = 15
y = 1
Now, solve for x by plugging in y into either one of the equations.
2x + 5y = 15
2x + 5 =15
2x = 10
x = 5
So x is 5 and y is 1.
Check by plugging in the values into the other equation.
5x + 10y = 35
5(5) + 10(1) = 35
25 + 10 = 35
35 = 35
The values are correct so, the answer for this problem is B (5, 1).
If I'm not mistaken.. the half-life should be 40,750 years.. so
y = 40,750
I got this by multiplying 25,000 by 1.63 and then if you divide by 2.. you get
20,375.. so one of those should be correct
Answer
4/5
Step-by-step explanation:
if i'm wrong let me know
