(3.1 x 10¹⁵) + (3.7 x 10¹³) in simplified form. Please hurry​

Plzzz i beg u so much asap ! what is the slope of this line? enter your answer in the box.

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

Worth 30 points! in this diagram, both polygons are regular. what is the value, in degrees, of the sum of the measures of angles abc and abd?