Which expression is equivalent to (7s - 21)-(3s - 4st + 7t)?

Find the missing factor. 7s2 + 25s + 12 = (s + 3)( ).

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

Worth 100 points need the answers asap first row -x^2 2x^2 (x/2)^2 x^2 x is less than 2 x is greater than 2 x is less than or equal to 2 x is greater than or equal to 2 second row -5 -5/2 4 5 •2 is less than x& x is less than 4 •2 is less than or equal to x & x is less than or equal to 4 •2 is less than or equal to x& x is less than 4 •2 is less than x& x is less than or equal to 4