Domik weights 30 pounds more than his sister
Together they weigh 330 pounds
Let "x" represent the weight of Dominik's sister, then his weight can be expressed as "x+30"
And their total weight can be calculated as:
[tex]x+(x+30)=330[/tex]From this expression you can calculate the value of x:
[tex]\begin{gathered} 2x+30=330 \\ 2x+30-30=330-30 \\ 2x=300 \\ \frac{2x}{2}=\frac{300}{2} \\ x=150 \end{gathered}[/tex]x=150 pounds
x+30=150+30=180 pounds
Dominik weights 180pounds and his sister 150 pounds