Answer:
10
Explanation:
The sum of a number and 4 is multiplied by 2, and the result is 28. In other words, letting the unknown number be x:
![2(x+4)=28](https://img.qammunity.org/2021/formulas/mathematics/high-school/3k60za6xwqw0v6w2goak3150pa0jmxuf8k.png)
Solve for x. Divide both sides by 2:
![x+4=14](https://img.qammunity.org/2021/formulas/mathematics/high-school/grocbomgnvlbu3vyhhoq8v21q5zpz5brtb.png)
Subtract 4 from both sides:
![x=10](https://img.qammunity.org/2021/formulas/mathematics/middle-school/yveq4wkntm80fiuxnqfce6qwd476ocdd80.png)
So, our unknown number is 10.
And we're done!