Answer:
![1)\ z=120\\\\2)\ g=46\\\\3)\ d=108\\\\4)\ r=39](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6rdy1kgrhx8ghli7yv9djjhbscrtwc5sdd.png)
Step-by-step explanation:
1) Given the equation:
![z/12=10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/afl25ouwjt9lkzsuird9htls4mfjryl5xn.png)
You can rewrite it in the following form:
![(z)/(12)=10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/loe17wgmiq4cg6e9m5281souoy6pd19zml.png)
You must solve for "z". To do it, you can multiply both sides of the equation by 12.
Then you get this solution:
![(12)((z)/(12))=(10)(12)\\\\z=120](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jc5iqdn6cw3sxat7t34n2vpbpkxltom44v.png)
2) The equation given is:
![5g=230](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jaaxymfhgcqdwkrp2sxkh4n59wss3syehw.png)
Now, in order to solve for the variable "g", you can divide both sides of the equation by 5.
Then you get the following result:
![(5g)/(5)=(230)/(5)\\\\g=46](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4lns8z8vytbt928k553j55vjvctkcf7z01.png)
3) Given the equation:
![d-21=87](https://img.qammunity.org/2020/formulas/mathematics/middle-school/y1ghhxerwouk8df8bmyg9ke00ks256u92g.png)
You can solve for "d" adding 21 to both sides of the equation.
So the value of "d" is:
![d-21+21=87+21\\\\d=108](https://img.qammunity.org/2020/formulas/mathematics/middle-school/p8bmec27ihwmrq66w7bl9a7682x55qzzei.png)
4) Having this equation:
![r + 35 = 74](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ajujgkln9r77dnjgwru5u1rrijccubrvru.png)
You must subtract 35 from both sides of the equation in order to find the value of the variable "r".
This is:
![r + 35-35 = 74-35\\\\r=39](https://img.qammunity.org/2020/formulas/mathematics/middle-school/98geojf7q0sf0lgn0cy31bv5x0nusyt6q5.png)