Answer:
(A) Always true
(B) Seldom true
Explanation:
(A) Both sides of an equation can be multiplied by the same number without this action changing the solution of the equation.
Keyword here is "number".
Multiplying both sides of an equation by an equal quantity (same number) will result in same solution after solving for the unknown in the equation. This is because that numeric quantity can always be removed by dividing both sides of the equation by it or by a factor (or multiple) of it.
EXAMPLE:
For a linear equation, 4x - 6 = 15x
let's find the solution, in other words solve for the unknown value X.
4x - 15x = 6
-11x = 6
x = -6/11
Now multiply both sides of the equation by 3.
3(4x - 6) = 3(15x)
12x - 18 = 45x ___new equation
Solve for X
12x - 45x = 18
-33x = 18
x = -18/33
Reduce the fraction to its simplest form by looking for a number that can divide both numerator and denominator without remainder. In other words, think of a number that is a factor of 18 and a factor of 33.
That common factor or highest common factor (HCF) is 3.
Go ahead and reduce the fraction.
x will be reduced to -6/11
(B) Both sides of an inequality can seldom be multiplied by the same number, without such action changing the solution set of the equation.
Inequalities are more complex. Operational signs even change sometimes, in the course of finding the solution set of the inequality.
Sometimes, multiplying both sides of an inequality by a given numeric quantity will change its solution set and sometimes, it won't.