Let's solve each of the inequalities step by step.
№1
a) \( 5x - 3 > 4 \)
- Add 3 to both sides: \[ 5x > 7 \]
- Divide by 5: \[ x > \frac{7}{5} \] \[ x > 1.4 \]
b) \( 4(x - 4) \leq 12 \)
- Distribute 4: \[ 4x - 16 \leq 12 \]
- Add 16 to both sides: \[ 4x \leq 28 \]
- Divide by 4: \[ x \leq 7 \]
Summary for №1:
- a) \( x > 1.4 \)
- b) \( x \leq 7 \)
№2
a) \( 0.2(x - 5) < 2 \)
- Multiply both sides by 10 (to eliminate the decimal): \[ 2(x - 5) < 20 \]
- Distribute: \[ 2x - 10 < 20 \]
- Add 10 to both sides: \[ 2x < 30 \]
- Divide by 2: \[ x < 15 \]
b) \( 0.4(x + 1) \geq -1 \)
- Multiply both sides by 10: \[ 4(x + 1) \geq -10 \]
- Distribute: \[ 4x + 4 \geq -10 \]
- Subtract 4 from both sides: \[ 4x \geq -14 \]
- Divide by 4: \[ x \geq -\frac{14}{4} \] \[ x \geq -3.5 \]
Summary for №2:
- a) \( x < 15 \)
- b) \( x \geq -3.5 \)
№3
\[ \frac{(x+2)^2(x-3)}{x+1} \leq 0 \]
Identify critical points:
- \( (x + 2)^2 = 0 \) ⇒ \( x = -2 \) (double root)
- \( x - 3 = 0 \) ⇒ \( x = 3 \)
- \( x + 1 = 0 \) ⇒ \( x = -1 \) (undefined)
Test intervals:
- For \( x < -2 \): Choose \( x = -3 \) → positive
- For \( -2 < x < -1 \): Choose \( x = -1.5 \) → negative
- For \( -1 < x < 3 \): Choose \( x = 0 \) → positive
- For \( x > 3 \): Choose \( x = 4 \) → positive
Summary of intervals:
- Negative or zero on: \( -2 \leq x < -1 \) (include -2, not -1)
Summary for №3:
\[ x \in [-2, -1) \]
№4
\[ |2x - 4| < 7 \]
This results in two inequalities:
\( 2x - 4 < 7 \) \[ 2x < 11 \] \[ x < 5.5 \]
\( 2x - 4 > -7 \) \[ 2x > -3 \] \[ x > -\frac{3}{2} \] \[ x > -1.5 \]
Summary for №4:
\[ -1.5 < x < 5.5 \]
№5
a) \( 4x + 2 < 7 \)
- Subtract 2 from both sides: \[ 4x < 5 \]
- Divide by 4: \[ x < \frac{5}{4} \] \[ x < 1.25 \]
b) \( 3(x + 2) \geq 11 \)
- Distribute: \[ 3x + 6 \geq 11 \]
- Subtract 6 from both sides: \[ 3x \geq 5 \]
- Divide by 3: \[ x \geq \frac{5}{3} \] \[ x \geq 1.6667 \]
Summary for №5:
- a) \( x < 1.25 \)
- b) \( x \geq 1.6667 \)
№6
a) \( 0.5(x - 4) < 4 \)
- Multiply both sides by 2: \[ x - 4 < 8 \]
- Add 4 to both sides: \[ x < 12 \]
b) \( 0.2(x + 2) \geq -2 \)
- Multiply both sides by 5: \[ x + 2 \geq -10 \]
- Subtract 2 from both sides: \[ x \geq -12 \]
Summary for №6:
- a) \( x < 12 \)
- b) \( x \geq -12 \)
№7
\[ \frac{(x-4)^2(x+3)}{x-2} \geq 0 \]
Critical points:
- From \( (x-4)^2 = 0 \): \( x = 4 \) (double root)
- From \( x + 3 = 0 \): \( x = -3 \)
- From \( x - 2 = 0 \): \( x = 2 \) (undefined)
Test intervals:
- For \( x < -3 \): Choose \( x = -4 \) → positive
- For \( -3 < x < 2 \): Choose \( x = 0 \) → negative
- For \( 2 < x < 4 \): Choose \( x = 3 \) → positive
- For \( x > 4 \): Choose \( x = 5 \) → positive
Summary for №7:
\[ x \in (-\infty, -3) \cup \left(2, 4\right] \]
№8
\[ |3x + 1| > 4 \]
This results in two inequalities:
\( 3x + 1 > 4 \) \[ 3x > 3 \] \[ x > 1 \]
\( 3x + 1 < -4 \) \[ 3x < -5 \] \[ x < -\frac{5}{3} \]
Summary for №8:
\[ x < -\frac{5}{3} \text{ or } x > 1 \]
You can now summarize these results for your exam preparation! If you have any specific questions or need further clarifications, feel free to ask!