To solve the inequality (4−7x)(x+2)/(x−3)(x−2)>0, we'll follow these steps:
Step 1: Find the critical points by setting the expression equal to zero and solving for x.
Step 2: Create intervals using the critical points.
Step 3: Test the expression within each interval to determine the sign of the expression.
Step 4: Identify the intervals where the expression is greater than zero.
Let's proceed with the steps:
Step 1: Find the critical points (where the expression is equal to zero):
(4−7x)(x+2)/(x−3)(x−2)=0
The expression is equal to zero when either 4−7x=0 or x+2=0 or (x−3)=0 or (x−2)=0.
Solving for x, we get:
4−7x=0
−7x=−4
x=74
x+2=0
x=−2
x−3=0
x=3
x−2=0
x=2
Step 2: Create intervals using the critical points:
We have four critical points: x=74, x=−2, x=3, and x=2.
The intervals are:
(−∞,−2)
(−2,74)
(74,2)
(2,3)
(3,∞)
Step 3: Test the expression within each interval to determine the sign:
Pick any value within each interval and evaluate the expression.
For x=−3 (in (−∞,−2)):
(4−7(−3))(−3+2)/(−3−3)(−3−2)=(−25)(−1)/(−6)(−5)=65>0
For x=0 (in (−2,74)):
(4−7(0))(0+2)/(0−3)(0−2)=(4)(2)/(−3)(−2)=34>0
For x=1 (in (74,2)):
(4−7(1))(1+2)/(1−3)(1−2)=(−3)(3)/(−2)(−1)=29>0
For x=2.5 (in (2,3)):
(4−7(2.5))(2.5+2)/(2.5−3)(2.5−2)=(10.5)(4.5)/(−0.5)(0.5)=−189<0
For x=4 (in (3,∞)):
(4−7(4))(4+2)/(4−3)(4−2)=(−20)(6)/(−1)(2)=60>0
Step 4: Identify the intervals where the expression is greater than zero:
The expression (4−7x)(x+2)/(x−3)(x−2) is greater than zero in the intervals:
(−∞,−2)