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Which ordered pair below is not a solution to f(x) = x² - 3x + 4?

(1) (0,4)
(2) (1.5,1.75)
(3) (5,14)
(4) (-1,6)

User Yaron Levi
by
4.4k points

1 Answer

1 vote

Answer:

(4) (-1,6)

Explanation:

f(x) = x² - 3x + 4

1) (0,4) ==>x=0 and f(x)=4

4 = 0² - 3(0) + 4

4 = 0 + 4

4 = 4 ==> true X

2) (1.5,1.75)==> x=1.5 and f(x)=1.75

1.75 = (1.5)² - 3(1.5) + 4

1.75 = 2.25 - 4.5 + 4

1.75 = 2.25 - 0.5

1.75 = 1.75 ==> true X

3) (5,14)

14 = (5)² - 3(5) + 4

14 = 25 - 15 + 4

14 = 10 + 4

14 = 14 ==> true X

4) (-1,6)

6 = (-1)² - 3(-1) + 4

6 = (|-1|)² - (-3) + 4 ==> the square of a negative number is equal to the square

of the absolute value of that number since the square of

a real number is always positive

6 = (1)²+ 3 + 4 ==> subtracting a negative number is equivalent to adding

the positive number

6 = 1 + 3 + 4

6 = 4 + 4

6 = 8 ==> false √√

Hence, the answer is (4) (-1,6).

User Thies
by
4.0k points