What is 0.0000345 in scientific notation

Which transformations could have occurred to map △abc to △a"b"c"? a rotation and a reflection a translation and a dilation a reflection and a dilation a dilation and a rotation

Use set builder notation to represent the following set: { -3, -2, -1, 0}

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