Which number represents 3.5 x 10^9

Given: hf || jk; hg ? jg prove: fhg ? kjg to prove that the triangles are congruent by asa, which statement and reason could be used as part of the proof? fgh ? kgj because vertical angles are congruent. jkg ? hfg because vertical angles are congruent. fhg ? jkg because right angles are congruent. hfg ? kjg because alternate interior angles are congruent.

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Factor the polynomial expression x6 – x3 – 20