Determine the change in internal energy ΔU (in kJ units) in a chemical system that absorbs 40.5 kJ of heat from the surroundings and performs 30.1 kJ work on the surroundings.

x = 21

x= -25

Step-by-step explanation:x^2+4-525=0

               x^21x+25x-525=0

           x{_x^2__ - __3.7__) +5^2 (_5^2.x___ -  _3.5^2.7)

                  x                x                     5^2                   5^2

          x(x^2-1-(3.7))+5^2(x-(3.7))=0

             x(x-27)+5^2(x-21)=0

          (x-21)((x(_x-21_)  + _5^2(x-21)_)=0

                       x-21               x-21

(x-21)(x+5^2)=0

(x-21)(x+25)=0

x- 21 =0

x+25= 0

x-21+21=21

(x+25)-25=-25

x=21

x+25-25=-25

x= 21

x= -25