2)、x+x=y+y+y

y+y+y=z+z+z+z

6y=2x+4z

3y=x+2z

x+y+z+z=80

x+2z+y=80

3y+y=80

4y=80

y=20 2x=3y=60 x=30。 x=2z z= 15

3) The length is increased by 8m, the area is increased by 48m, and the width is 48/8=6.

Width plus 6 meters area plus 48 square meters is often. . . . . eight

It turned out to be 48 square meters.

3) The length is 4m, and the area is increased by 40m2; The width is 10.

The width is reduced by 3 meters, the area is reduced by 90 square meters and the length is 30.

The area is 300

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