Call the number of hours babysitting
![B](https://img.qammunity.org/2019/formulas/mathematics/college/olo9c14ssxz5ak3wo84ow8dtdgnlpgp7vb.png)
and the number of hours walking dogs
![D](https://img.qammunity.org/2019/formulas/mathematics/college/dd6zjgndam9b55yvulm98wwqciwp63kkwr.png)
.
We know that she earns $6/hr for babysitting or
![6B](https://img.qammunity.org/2019/formulas/mathematics/college/1uopbbkeenrlrz8lss65xzgu3mtntynmrd.png)
, and $5/hr walking dogs or
![5D](https://img.qammunity.org/2019/formulas/mathematics/college/y9m40r3hx8gw96rwwarq6ssqi9uq8gykc2.png)
. We also know the total money is $43 and the total time is 8hours. Therefore:
![B+D=8](https://img.qammunity.org/2019/formulas/mathematics/college/wi3620zs42dp4f819lcbaaklertfpcc8hi.png)
![6B+5D=43](https://img.qammunity.org/2019/formulas/mathematics/college/gawbrf90jy0zfad6o2960jh99tcok8lqq2.png)
To solve: First rearrange equation 1 to solve for either
![B](https://img.qammunity.org/2019/formulas/mathematics/college/olo9c14ssxz5ak3wo84ow8dtdgnlpgp7vb.png)
or
![D](https://img.qammunity.org/2019/formulas/mathematics/college/dd6zjgndam9b55yvulm98wwqciwp63kkwr.png)
(doesn't matter which, I'll use
![B](https://img.qammunity.org/2019/formulas/mathematics/college/olo9c14ssxz5ak3wo84ow8dtdgnlpgp7vb.png)
):
![B=8-D](https://img.qammunity.org/2019/formulas/mathematics/college/1lkawbo31ubhnmt94n8w1z4op2uml5fppg.png)
Now substitute into equation 2:
![6(8-D)+5D=43](https://img.qammunity.org/2019/formulas/mathematics/college/x4fj36jtp97xnusu5ph399x63clkvvhr8g.png)
and solve for
![D](https://img.qammunity.org/2019/formulas/mathematics/college/dd6zjgndam9b55yvulm98wwqciwp63kkwr.png)
![48-6D+5D=43](https://img.qammunity.org/2019/formulas/mathematics/college/7f3vej74tefss3d8spqz4cb0ifc821vfd9.png)
![-D=-5](https://img.qammunity.org/2019/formulas/mathematics/college/r7olvzuoup9r833hbj28dwcwrn2u7nd6m3.png)
![D=5](https://img.qammunity.org/2019/formulas/mathematics/college/d5twfzwhk9en65s3jgesf1v7niz9udjj86.png)
Now backsubstitute to solve for
![B](https://img.qammunity.org/2019/formulas/mathematics/college/olo9c14ssxz5ak3wo84ow8dtdgnlpgp7vb.png)
:
![B=8-D](https://img.qammunity.org/2019/formulas/mathematics/college/1lkawbo31ubhnmt94n8w1z4op2uml5fppg.png)
![B=8-5](https://img.qammunity.org/2019/formulas/mathematics/college/2w5jcjtifrdscq1s50b0xewl84hedjs2ic.png)
![B=3](https://img.qammunity.org/2019/formulas/mathematics/middle-school/3uqxwlrqhgyxq1apaoje0vlnnpa2r04ody.png)
She babysat for 3 hours and walked dogs for 5.
To check our work:
![6B+5D=43](https://img.qammunity.org/2019/formulas/mathematics/college/gawbrf90jy0zfad6o2960jh99tcok8lqq2.png)
![6(3)+5(5)=43](https://img.qammunity.org/2019/formulas/mathematics/college/dzjtjjplrau7zk76vpz7z4nq3ab6hfofl7.png)
![18+25=43](https://img.qammunity.org/2019/formulas/mathematics/college/svsx1yy1vpy6edeclkf2tmr78e8akfmet6.png)
![43=43](https://img.qammunity.org/2019/formulas/mathematics/college/xjbvulndtwwj8kfc8en4r73r9g0nw5q21k.png)
CHECKS