Math Problem Statement

Do 16-18

Do 16-18

Solution

I can see your uploaded image clearly, and I'll solve problems 16, 17, and 18 from it. Let's get started!


Problem 16:

Equation: 9x² = 4 + 7x

Solution:

  1. Move all terms to one side to set the equation to 0: 9x27x4=09x^2 - 7x - 4 = 0

  2. Use the quadratic formula: x=B±B24AC2Ax = \frac{-B \pm \sqrt{B^2 - 4AC}}{2A} For A=9A = 9, B=7B = -7, and C=4C = -4, the formula becomes: x=(7)±(7)24(9)(4)2(9)x = \frac{-(-7) \pm \sqrt{(-7)^2 - 4(9)(-4)}}{2(9)}

  3. Simplify: x=7±49+14418x = \frac{7 \pm \sqrt{49 + 144}}{18} x=7±19318x = \frac{7 \pm \sqrt{193}}{18}

Thus, the two solutions are: x=7+19318orx=719318x = \frac{7 + \sqrt{193}}{18} \quad \text{or} \quad x = \frac{7 - \sqrt{193}}{18}


Problem 17:

Equation: 5x + 9x = 4

Solution:

  1. Combine like terms: 14x=414x = 4

  2. Solve for xx: x=414=27x = \frac{4}{14} = \frac{2}{7}


Problem 18:

Equation: 2x² - 36 = x

Solution:

  1. Move all terms to one side: 2x2x36=02x^2 - x - 36 = 0

  2. Use the quadratic formula: x=B±B24AC2Ax = \frac{-B \pm \sqrt{B^2 - 4AC}}{2A} For A=2A = 2, B=1B = -1, and C=36C = -36, the formula becomes: x=(1)±(1)24(2)(36)2(2)x = \frac{-(-1) \pm \sqrt{(-1)^2 - 4(2)(-36)}}{2(2)}

  3. Simplify: x=1±1+2884x = \frac{1 \pm \sqrt{1 + 288}}{4} x=1±2894x = \frac{1 \pm \sqrt{289}}{4}

  4. Since 289=17\sqrt{289} = 17, we get: x=1+174orx=1174x = \frac{1 + 17}{4} \quad \text{or} \quad x = \frac{1 - 17}{4}

  5. The two solutions are: x=184=4.5orx=164=4x = \frac{18}{4} = 4.5 \quad \text{or} \quad x = \frac{-16}{4} = -4


Final Answers:

  • Problem 16: x=7+19318x = \frac{7 + \sqrt{193}}{18} or x=719318x = \frac{7 - \sqrt{193}}{18}
  • Problem 17: x=27x = \frac{2}{7}
  • Problem 18: x=4.5x = 4.5 or x=4x = -4

Would you like more detailed steps for any part of the solutions? 😊


Here are 5 related questions for further practice:

  1. Solve 3x2+5x2=03x^2 + 5x - 2 = 0 using the quadratic formula.
  2. Solve the linear equation 6x4=106x - 4 = 10.
  3. Solve 7x22x+1=07x^2 - 2x + 1 = 0.
  4. Factor the quadratic expression x25x+6x^2 - 5x + 6.
  5. Solve 4x+3=152x4x + 3 = 15 - 2x.

Tip: Always simplify your equations first before applying formulas like the quadratic formula!

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Linear Equations

Formulas

Quadratic formula: x = (-B ± √(B^2 - 4AC)) / 2A
Linear equation solving

Theorems

Quadratic formula theorem

Suitable Grade Level

Grades 8-10