ElectricPavlov

Move decimal point over 4 spaces    2.077 x 10^-4

Funny !  I was thinking the same thing.

Do you have soem choices from which to select ?     Any pair (x,y) that you are given have to satisfy the y= -2x+5 equation when you susbstitute  'x' and ' y' into it.....

I think we will need the mass of 'the station'  and orbit altitude to answer this question....

2x-(5-x)=13+2x

2x-5 + x = 13 + 2x

3x - 5 = 13 + 2x

x -5 = 13

x = 18

1.  x = adult tix     revenue from adult tix = $ 7.5x

     (115-x) = kidz tix  revenue from kidx = $3.00(115-x)    

the revenues from BOTH tix added together = $ 678

7.5x + 3 (115-x) = 678

4.5x = 678-345

4.5x =333

x= adult tix = 74

2.   Pure silver amount  = x    x(31.48) =  cost of pure silver

      Alloy = 50 oz       50(22.35) = cost of alloyT

The two costs added together =  (x+50)(25.98)

31.48 x + 50(22.35) = (x+50)(25.98)

31,48 x + 1117 .5 = 25.98x + 1299

5.5x = 181.5

x= amount of pure silver = 33 ounces

3....similar to 2....let me know if you need more help....

Kinetic Energy = 1/2  m v^2

                         = 1/2 (1000)(2^2) = 2000 j    (kg-m^2/s^2)

The fractions input helper has never operated for me  YMMV....   click on the little gray bars in the display area to find the fraction helper....

It had it 'roots' exposed?

If you rewrite the FIRST equation    x = 9 + 3y     substitute this value of x into the second equation

x + 4y = 2

9+3y+4y=2

7y = -7

y=-1         Substitute this into one of the original equations to find x

x - 3 (-1) = 9

x +3 = 9

x = 6