A scientist wishes to represent the location of an earthquake in California. Which type of model is most appropriate for this purpose?

Seismograph?

Explanation:

If an earthquake happens, seismologists use seismic waves that are detected with seismographs, to locate the epicenter of an earthquake, and also to estimate the strength and duration of the earthquake

b. the carbon cycle ensures living things have a source of hydrogen

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)