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Solve the following quadratic inequality.

(x+3) (2x - 5) > 0
OIE (-∞, -4) U (7, ∞0)
Ox€ (-∞, -4) U (₁00)
0 SE (-∞, -6) U (², 0.
OXE (-∞, -3) U ({, ∞)

1 Answer

3 votes

The solution to the inequality is D. x∈(−∞,−4)∪( 5/2 ,∞). The correct answer is D. x∈(−∞,−4)∪(5/2 ,∞).

To solve the quadratic inequality (x+4)(2x−5)>0, let's find the critical points by setting each factor equal to zero:

x+4=0 gives x=−4.

2x−5=0 gives x= 5/2.

These critical points divide the number line into three intervals:

(−∞,−4),

(−4, 5/2 ), and ( 5/2 ,+∞).

Now, let's test a value in each interval to determine where the inequality holds true:

Test a value less than −4, say x=−5.

(−5+4)(2(−5)−5)=(−1)(−15)=15>0. So, the inequality holds in (−∞,−4).

Test a value between −4 and 5/2 , say x=0.

(0+4)(2(0)−5)=(4)(−5)=−20<0. So, the inequality doesn't hold in (−4, 5/2 ).

Test a value greater than 5/2 , say x=3.

(3+4)(2(3)−5)=(7)(1)=7>0. So, the inequality holds in (5/2 ,+∞).

Therefore, the solution to the inequality is D. x∈(−∞,−4)∪( 5/2 ,∞).

The correct answer is D. x∈(−∞,−4)∪(5/2 ,∞)

Question

Solve the following quadratic inequality.

(x+4) (2x - 5) > 0

A. IE (-∞, -4) U (7, ∞0)

B. x€ (-∞, -4) U (1, 00)

C. SE (-∞, -6) U (2/3, 0.)

D. x€ (-∞, -4) U (5/2,∞)

User Mickel
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