Question

a) X - 5 = 2x , U = Q

b) X + 9 = 2, U = N

c) 7 - X = 2 +X , U = Z

d) -X = 3X + 5 , U = Q

Answer 1

a) x -5 = 2x

2x -x = 5

x=5

b) x + 9 = 2

x = 2 -9

x = -7

c) 7 -x = 2 +x

-x -x = 2 -7

-2x = -5 ×(-1)

2x = 5

x = 2,5

d) -x = 3x + 5

-x -3x = 5

-4x = 5 ×(-1)

4x = -5

x = -5/4