Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
1. Conditional Statements
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Exercise 23 Page 447

Does x=9 solve the equation?

Type of statement Statement True or False?
Conditional statement If 3x-7=20, then x=9 True
Converse statement If x=9, then 3x-7=20 True
Inverse statement If 3x-7≠20, then x≠9 True
Contrapositive statement If x≠9, then 3x-7≠20 True
Practice makes perfect

Let's consider each of the statements one at a time using the given p and q. p: & 3x-7=20 q: & x=9

Conditional Statement

We can write the conditional statement, p→ q, in an if-then form. If 3x-7=20, then x=9.To determine if this is true, we substitute the value of x into the equation and check if the left-hand side and right-hand side are equal.
3x-7=20
3( 9)-7? =20
27-7? =20
20=20
The solution is correct. Therefore, we can claim that the conditional statement is true.

Converse

The converse of a conditional statement, q→ p, exchanges the hypothesis and the conclusion of the conditional statement. If x=9 , then 3x-7=20 . By the same logic the conditional statement is true, the converse of the conditional statement is also true.

Inverse

The inverse of a conditional statement, ~ p→ ~ q, requires us to negate the hypothesis and the conclusion of the conditional statement. If 3x-7≠ 20, then x≠ 9. This is a true statement. If 3x-7 does not equal 20 the value of x cannot be 9, as this would make 3x-7 equal 20.

Contrapositive

The contrapositive of a conditional statement, ~ q→ ~ p, starts out with the converse of the conditional statement. Then we have to negate the hypothesis and the conclusion. If x≠ 9 , then 3x-7≠ 20 . By the same logic we know that the previous statements are true, we know that the contrapositive is true.