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Algebra methods
Rational expressions, root equations, interval notation and linear programming: methods worked in steps rather than a formula to fill in. Every question is drawn afresh when you ask, and every solution is written out.
Rational expressions
Simplify a rational expression
Simplify the expression, and state the values of x for which it is not defined.
(x² − 7x + 10)/(5x − 25)
Separate several numbers with a semicolon or a comma: 2; −3.
Add two rational expressions
Write as one fraction, and state the values of x for which the expression is not defined.
5/(x + 5) + 2/(x − 4)
Separate several numbers with a semicolon or a comma: 2; −3.
Subtract two rational expressions
Write as one fraction, and state the values of x for which the expression is not defined.
1/(x + 3) − 5/(x + 4)
Separate several numbers with a semicolon or a comma: 2; −3.
Solve a rational equation
Solve the equation.
4/(x − 1) = 2/(x + 4)
Separate several numbers with a semicolon or a comma: 2; −3.
Radical equations
A root equation, and the false root
Solve the equation, and check every root you find.
√(−2x + 19) = x − 2
Separate several numbers with a semicolon or a comma: 2; −3.
Isolate the root, then solve
Solve the equation, and check every root you find.
√(5x + 19) + 2 = x + 3
Separate several numbers with a semicolon or a comma: 2; −3.
Rules for inequalities
From inequality to interval
Write the inequality in interval notation.
−1 < x ≤ 8
From interval to inequality
Write the interval as an inequality.
(−∞, 1)
Solve a linear inequality, step by step
Solve the inequality. Give the answer as an inequality and in interval notation.
2x − 5 > 6x − 25
Solve a double inequality
Solve the double inequality. Give the answer as an inequality and in interval notation.
6 ≤ −4x + 2 < 26
Linear programming
Largest value on a bounded region
What is the largest value of z = x + y when
- x ≥ 0
- y ≥ 0
- 5x + y ≤ 25
- 5x + 4y ≤ 40
Smallest value on an open region
What is the smallest value of z = 5x + 2y when
- x ≥ 0
- y ≥ 0
- 2x + y ≥ 7
- x + y ≥ 4
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