scientific notation help ! they have different units, not sure how to work with them. If you answer one of the questions that willl be fine ^_^

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

Louise measured the perimeter of her rectangular scrapbook to be 154 cm. if the scrapbook is 45 cm wide, how long is the scrapbook?

1) in triangle the, what is the measure of angle t (in degrees)? 2) in triangle bat, the measure of angle b is 66∘, and the measure of angle t is 77∘.what is the measure of the exterior angle at a (in degrees)?