Question

Which property justifies this statement?

If x=−2x=−2, then 5x=−105x=−10.

Subtraction Property of Equality
Transitive Property of Equality
Multiplication Property of Equality
Symmetric Property of Equality

Answer 1

Multiplication Property of Equality

is possible to notice this property by looking its definition.
If a = b then a·c = b·c.

Answer 2

x = - 2 x = - 2
If we multiply it by 5:
x = - 2 x = - 2 / * 5
then:
5 x = - 2 * 5 x = - 2 * 5
5 x = - 10 x = - 10
Answer:
C ) Multiplication Property of Equality.