Write 0.0000003105 in scientific notation

What is the measure of angle z in this figure? enter your answer in the box. z = ° two intersection lines. all four angles formed by the intersecting lines are labeled. clockwise, the angles are labeled 43 degrees, x degrees, y degrees, and z degrees.

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Multiply and simplify. 2x2y3z2 · 4xy4x2 how to do?