Simultaneous Equations: hg+hm=14000 13760-(0.1xhg+17.9x0.052xhm)=5000

[Sam Brown]

Hi,

Can someone please help me with the below simultaneous equations, I have the answers below from a work book I am completing but I cannot get the correct answer. Any help would be greatly appreciated.

h_g+h_m=14000

13760-(0.1xh_g+17.9x0.052xh_m)=5000

Answer:
h_g=5141
h_m=8859

Thanks

Sam

 

[Deleted member 4993]

Hi,

Can someone please help me with the below simultaneous equations, I have the answers below from a work book I am completing but I cannot get the correct answer. Any help would be greatly appreciated.

h_g+h_m=14000.........................................................(1)

13760-(0.1xh_g+17.9x0.052xh_m)=5000.......................(2)

Answer:
h_g=5141
h_m=8859

Thanks

Sam

h_g+h_m=14000

h_m=14000 - h_g ..............................................(3)

Now substitute h_m in (2) using (3).

Continue.......

 

[Dr.Peterson]

h_g+h_m=14000

13760-(0.1xh_g+17.9x0.052xh_m)=5000

Answer:
h_g=5141
h_m=8859

I would tend to simplify equation (2) before doing the substitution, though in this case it doesn't make much difference.

If you still don't get the right answer, please show your actual work, so we can see what might be going wrong. I do get the stated answer (rounded to the nearest integer).

 

[JeffM]

Hi,

Can someone please help me with the below simultaneous equations, I have the answers below from a work book I am completing but I cannot get the correct answer. Any help would be greatly appreciated.

h_g+h_m=14000

13760-(0.1xh_g+17.9x0.052xh_m)=5000

Answer:
h_g=5141
h_m=8859

Thanks

Sam

Hi Sam. Welcome to Free Math Help.

We cannot possibly show you where are making an error in your work unless you show us that work.

Alternatively, you can use the suggestions given to you to try again. But then you will not learn what you did wrong in the first place.

 

[Sam Brown]

Simultaneous Equations

Hi All,

Thanks for your help, really appreciated, I have since fumbled my way through it to get the below answer, I am still 43ft from the workbook answer, do you think this matters or is my process correct?

Substituting into (2)

13760-(0.1xhg+17.9X0.052x(14000-hg)=5000

1.hg-1hg=-0.9hg

13760-(17.9x0.052x(14000-0.9hg)=5000

+(17.9x0.052x(14000-0.9hg)

13760=5000+(17.9x0.052x(14000-0.9hg)

-5000

13760-5000=17.9x0.052x(14000-0.9hg)

8760=17.9x0.052x(14000-0.9hg)

/17.9x0.052x

8750/(17.9x0.052)=14000-0.9hg

+0.9hg

0.9hg+8760/(17.9x0.052)=14000

-8760/(17.9x0.052)

0.9hg=14000-8760/(17.9x0.052)

hg=(14000-(8760/(17.9x0.052)))/0.9

hg=5098.6ft and he work book answer was 5141ft

Any help with simplifying the way I got the answer would be greatly appreciated.

Thanks again guys. This is a big learning curve for me but am really enjoying the challenge.

Thanks

Sam

 

[stapel]

I have since fumbled my way through it to get the below answer, I am still 43ft from the workbook answer, do you think this matters or is my process correct?

Being able to see what you've done can be vitally important, yes!

(1) h_g+h_m=14000

(2) 13760-(0.1xh_g+17.9x0.052xh_m)=5000

Should we assume that "x" is a variable or (as seems more likely here) that it is being used to indicate multiplication? If the latter, is there any particular reason why the multiplications have not been simplified, to get a reduced system of equations?

. . . . .\(\displaystyle \mbox{(1) }\, h_g\, +\, h_m\, =\, 14000\)

. . . . .\(\displaystyle \mbox{(2) }\, 0.1\, h_g\, +\, 0.9308\, h_m\, =\, 18760\)

Substituting [the solved-for-h_m version of (1)] into (2)

13760-(0.1*h_g+17.9*0.052*(14000-h_g)=5000

1.hg-1hg=-0.9hg

Where did the last line above come from? You started here:

. . . . .\(\displaystyle 13760\, -\, \left(0.1\,h_g\, +\, 0.9308\, \left(14000\, -\, h_g\right)\right)\, =\, 5000\)

. . . . .\(\displaystyle 13760\, -\, \left(0.1\, h_g\, +\, 0.9308\, (14000)\, +\, 0.9308\, \left(-h_g\right)\right)\, =\, 5000\)

. . . . .\(\displaystyle 13760\, -\, \left(0.1\, h_g\, +\, 13031.2\, -\, 0.9308\, h_g\right)\, =\, 5000\)

How did you get from this to the last line quoted above?

Please show all of your steps. Thank you!

 

[Steven G]

Hi All,

Thanks for your help, really appreciated, I have since fumbled my way through it to get the below answer, I am still 43ft from the workbook answer, do you think this matters or is my process correct?

Substituting into (2)

13760-(0.1xhg+17.9X0.052x(14000-hg)=5000

1.hg-1hg=-0.9hg

13760-(17.9x0.052x(14000-0.9hg)=5000

+(17.9x0.052x(14000-0.9hg)

I do agree that .1hg-1hg=-0.9hg, but this is not needed in this problem. Why not? You need to distribute the 17.9X0.052 to the hg (as well as to the 14000).

So you really have 0.1hg - 17.9X0.052hg. Compute this.