Answer:
John work as a security guard job 27 hours and as a landscaper 33 hours.
Explanation:
Given:
John works two jobs.
As a security guard he earns $8.50 per hour and as a landscaper he earns $14 per hour.
One week John worked a total of 60 hours and earned $691.50.
Now, to find hours he work at each job.
Let the job of security guard be
hours.
And the job of landscaper be
hours.
So, the total hours John worked in a week:
![x+y=60.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8vka311g3u5p2g1f1ep7huq0ch1xh9o3az.png)
⇒
............( 1 )
Now, the money earned by John in a week:
![8.50x+14y=691.50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6mrlzr35x2wbu3aaiu36bhkcolx03z05c9.png)
Putting the equation ( 1 ) in the place of
:
⇒
![8.50x+14(60-x)=691.50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/rda5cuj2rpciijiwcxnea05s5ugt1f8crw.png)
⇒
![8.50x+840-14x=691.50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tebf6e2phy8qcqgagqfjhurpl3z6vj6d1x.png)
Moving variables on one side and the other we get:
⇒
![840-691.50=14 x-8.50x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8k05ls2l3xr5i10ckhb0olaat18qq5a57x.png)
⇒
![148.50=5.50x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/65l9b7sqomf8n7dged1dogg30o6mqzs4ng.png)
Dividing both sides by 5.50 we get:
⇒
![27=x](https://img.qammunity.org/2020/formulas/mathematics/high-school/9v5n1qkpal1n2jy0cxlwijqvhs0fk93ggn.png)
As a security guard job he worked 27 hours.
Putting the value of in
equation ( 1 ) we get:
![y=60-27](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gpvlj5p5bonxay42qmyup3vjminz2n3khr.png)
⇒
![y=33.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/545dfk0dhcqihfimsh2raqugvdej5qq0fb.png)
As a landscaper he worked 33 hours.
Therefore, John work as a security guard job 27 hours and as a landscaper 33 hours.