PLEASE HELP 20 POINTS One day, River writes down the numbers $1,$ $2,$ $\dots,$ $999.$ What is the sum of all the digits that River wrote down?

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

Which expressions are equivalent to -7+3(-4e-3)? choose all answers that apply: choose all answers that apply: a -4(3e+4)? 4(3e+4) b 12e12e c none of the above

Will mark determine whether the conjecture is true or false. give a counterexample for any false conjecture. given: points r, s, and t conjecture: r, s, and t are coplanar. a) false; the points do not have to be in a straight line. b) true c) false; the points to not have to form right angles. d) false; one point may not be between the other two.