Question 432429
so democrats(d)+republicans(r)=434
democarts(d) +30=republicans(r)

so d+r=434
d+30=r

Lets substitue the second equation into the first:

d+(d+30)=434
2d+30=434
2d=404
d=202

202 democrats
202+30=232 republicans

Hope this helps:-)