DrDelMath Intermediate Algebra Examples
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1. Is 5 a solution of 3x + 2 = 8 ?
If x is replaced with 5 the equation becomes 15 + 2 = 8 which is FALSE.
Therefore 5 is not a solution of the equation.
2. Is 5 a solution of 3x + 2 < 8 ?
If x is replaced with 5 the inequality becomes 15 + 2 < 8 which is FALSE.
Therefore 5 is not a solution of the inequality.
If x is replaced with 5 the inequality becomes 15 + 2 > 8 which is TRUE.
Therefore 5 is a solution of the inequality.
4. Is
a solution of 3x + 2 = 0 ?
If x is replaced with
the equation becomes 2 + 2 = 0 which is FALSE.
Therefore
fails to satisfy the definition of solution.
Hence
is not a solution of the equation.
a solution of 3x + 2 = 0 ?
If x is replaced with
, the equation becomes -2 + 2 = 0 which is TRUE.
Therefore
satisfies the definition of solution.
Hence
is a solution of the equation.
6. Is -4 a solution of x2 = 16 ?
If x is replaced with -4, the equation becomes 16 = 16 which is TRUE.
Therefore -4 satisfies the definition of solution.
Hence -4 is a solution of the equation.
7. Is {-4} the solution set for x2 = 16 ?
From Example 4, we know that -4 is a solution of the equation.
That means -4 is in the solution set for the equation.
However, 4 is also a solution of the equation and 4 is not in the set {-4}.
Therefore {-4} is not the solution set for the equation.
8. What is the solution set for x = 7 ?
It is pretty obvious that the only number which makes the equation a true statement is 7.
Therefore the solution set for the equation is {7}.
Notice this is a simplest equation. One of the VERY useful properties of a
simplest equation is the fact that its solution set is obvious.
9. What is the solution set for x =
?
It is pretty obvious that the only number which makes the equation a true statement is
.
Therefore the solution set for the equation is {
}.
Notice this is a simplest equation. One of the VERY useful properties of a
simplest equation is the fact that its solution set is obvious.
10. What is the solution set for x =
?
It is pretty obvious that the only number which makes the equation a true statement
is
.
Therefore the solution set for the equation is
{
}.
Notice this is a simplest equation. One of the VERY useful properties of a simplest
equation is the fact that its solution set is obvious.
11. Is 4 a solution for 2x - 7 > 3?
If x is replaced with 4 the inequality becomes 8 - 7 > 3 which is FALSE.
Therefore 4 is not a solution of the inequality.
12. Is 4 a solution for 2x - 7 = 3?
If x is replaced with 4 the equation becomes 8 - 7 = 3 which is FALSE.
Therefore 4 is not a solution of the equation.