Math Problem Statement

Solution exercice

Solve the inequalities and equations as shown in the exercise.

Solution

Here is the solution for the exercise based on the image provided:


Exercise 2: Solve the following inequalities and equations


1. Solve the inequalities:

(a) 3x+233x + 2 \leq 3

  • Subtract 2 from both sides: 3x13x \leq 1
  • Divide by 3: x13x \leq \frac{1}{3}

Solution: x(,13]x \in \left(-\infty, \frac{1}{3} \right]


(b) 2x322x - 3 \geq 2

  • Add 3 to both sides: 2x52x \geq 5
  • Divide by 2: x52x \geq \frac{5}{2}

Solution: x[52,)x \in \left[\frac{5}{2}, \infty \right)


(c) x26x+50x^2 - 6x + 5 \geq 0

  • Solve the quadratic equation x26x+5=0x^2 - 6x + 5 = 0 by factoring: (x1)(x5)=0(x - 1)(x - 5) = 0
  • Roots: x=1x = 1 and x=5x = 5
  • Test intervals (,1)(-\infty, 1), (1,5)(1, 5), (5,)(5, \infty) using a sign table:
    • For x(,1):(x1)(x5)>0x \in (-\infty, 1): (x - 1)(x - 5) > 0
    • For x(1,5):(x1)(x5)<0x \in (1, 5): (x - 1)(x - 5) < 0
    • For x(5,):(x1)(x5)>0x \in (5, \infty): (x - 1)(x - 5) > 0

Solution: x(,1][5,)x \in (-\infty, 1] \cup [5, \infty)


(d) x26x+5<0x^2 - 6x + 5 < 0

  • Use the roots from part (c): x=1x = 1 and x=5x = 5
  • From the sign table:
    • For x(1,5):(x1)(x5)<0x \in (1, 5): (x - 1)(x - 5) < 0

Solution: x(1,5)x \in (1, 5)


2. Solve in R\mathbb{R}:

System of equations:

x + y = -8 \\ e^x - y = 3 \end{cases}$$ **Step 1: Solve for $$y$$ in the first equation:** $$y = -8 - x$$ **Step 2: Substitute $$y = -8 - x$$ into the second equation:** $$e^x - (-8 - x) = 3$$ $$e^x + 8 + x = 3$$ $$e^x + x + 8 = 3$$ $$e^x + x = -5$$ **Step 3: Solve $$e^x + x = -5$$:** This equation requires a numerical or graphical approach as it cannot be solved algebraically. Approximate solutions may be obtained using numerical methods such as Newton's method. --- Would you like me to expand on any of these steps or solve $$e^x + x = -5$$ numerically? Let me know! --- ### 5 Related Questions: 1. How do you construct a sign table for quadratic inequalities? 2. Can you explain how to solve nonlinear systems of equations numerically? 3. What are the key differences between strict inequalities and non-strict inequalities? 4. How can we test solutions graphically for equations involving $$e^x$$? 5. What are alternative ways to solve quadratic equations besides factoring? --- ### Tip: Always double-check your solutions to inequalities by substituting boundary points and testing intervals for accuracy!

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Math Problem Analysis

Mathematical Concepts

Linear inequalities
Quadratic inequalities
System of equations
Exponential equations

Formulas

Quadratic equation: ax^2 + bx + c = 0
Substitution method for systems of equations

Theorems

Zero-product property
Properties of exponential functions

Suitable Grade Level

Grades 10-12