5A

Harder equations and inequalities

Solving linear equations with several algebraic fractions, and solving linear inequalities with fractions, brackets and negative coefficients.

Several fractions

Example 1●●●

Solve $\dfrac{x - 2}{3} - \dfrac{x + 1}{4} = 1$.

$4(x - 2) - 3(x + 1) = 12$
Multiply every term by 12
$4x - 8 - 3x - 3 = 12$, so $x = 23$.

Inequalities

Example 2●●

Solve $-3(x - 2) < 12$.

$x - 2 > -4$
Divide by −3 and reverse
$x > -2$
Flashcards
Clear several fractions
Multiply every term by the LCD.
Reverse the inequality when
Multiplying or dividing by a negative
$-x le 4$
$x \ge -4$
Practice
  1. Solve $\dfrac{x - 2}{3} - \dfrac{x + 1}{4} = 1$.

  2. Solve $-3(x - 2) < 12$.

  3. Solve $\dfrac{2x - 3}{5} \ge 3$.

  4. Solve $4 - \dfrac{x}{2} \le 1$.

  5. Solve $\dfrac{x + 3}{2} = \dfrac{x + 13}{4}$.

  6. Solve $\dfrac{x}{2} + \dfrac{x}{3} = -5$.

  7. What is the smallest integer $x$ that satisfies $3x - 7 > 2(x - 1)$?

  8. Solve $\dfrac{3x}{4} - \dfrac{x}{2} = 1$.

More questions

New numbers every time. Keep going until you get five in a row.

Formula sheet