5x + 3(x - 4) = 60
please solve

The lines marked by the letters a, b, and c on the map above represent a. chains of volcanoes b. earthquake fault lines c. thin strips of heavy forests d. major rivers that flow from north to south

The layers of earth are based on what two sets of characteristics?

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks