Question

Tim so nguyen x biet:

a, 82-(15+x)=72

b,(x-9).(x+2)=0

Answer 1

 

a, 82-(15+x)=72

         15+x=82-72=10

              x=10-15

              x=-5

 b,(x-9).(x+2)=0

=>x-9=0 hoặc x+2=0

nếu x-9=0

=>   x  =0+9

=>   x  =9

nếu x+2=0

=>    x  =0-2

=>    x  =-2

vậy x=9 hoặc x=-2

tick nha

Answer 2

a.

82-(15+x)=72

(15+x)=82-72

15+x=10

x=10-15

x=-5