Question

vWhich of the following equations has no solution?


7
x
−
3
x
−
4
=
4


7
x
−
3
x
+
4
=
4


3
(
2
x
−
4
)
=
6
(
x
−
2
)


3
(
2
x
−
4
)
=
6
(
x
+
2
)

Answer 1

3(2x − 4) = 6(x + 2)

Reason: 3(2x − 4) = 6x − 12 and 6(x + 2) = 6x + 12, so the equation becomes 6x − 12 = 6x + 12. Subtracting 6x gives −12 = 12, a contradiction, so there is no solution.