Ultimate Algebra Lecture Notes: Solving Algebra 1 Questions
Welcome to Ultimate Algebra! This lecture covers various types of Algebra 1 problems and the easiest methods to solve them. For a more comprehensive course, visit our website at ultimatealgebra.com.
One-Step Equations
Example 1: Solve x + 2 = 5
- Objective: Isolate x.
- Steps:
- Subtract 2 from both sides.
- The equation simplifies to x = 3.
Two-Step Equations
Example 2: Solve 2x + 3 = 11
- Objective: Isolate x.
- Steps:
- Subtract 3 from both sides: 2x = 8.
- Divide by 2: x = 4.
Multi-Step Equations
Example 3: Solve 3x^2 + 8 = 20
- Objective: Isolate x.
- Steps:
- Subtract 8 from both sides.
- Divide by 3.
- Take the square root.
- Result: x = 2.
Equations with Variables on Both Sides
Example 4: Solve 4x + 5 = 9 + 2x
- Objective: Isolate x.
- Steps:
- Subtract 2x from both sides: 2x + 5 = 9.
- Subtract 5 from both sides: 2x = 4.
- Divide by 2: x = 2.
Absolute Value Equations
Example 5: Solve |x + 3| = 7
- Objective: Solve for x.
- Steps:
- Set up two equations: x + 3 = 7 and x + 3 = -7.
- Solve both: x = 4 and x = -10.
Example 6: Solve |x + 1| + 6 = 9
- Objective: Isolate the absolute value term.
- Steps:
- Subtract 6 from both sides: |x + 1| = 3.
- Set up two equations: x + 1 = 3 and x + 1 = -3.
- Solve both: x = 2 and x = -4.
Radical Equations
Example 7: Solve √(x + 3) - 2 = 1
- Objective: Isolate the radical.
- Steps:
- Add 2 to both sides: √(x + 3) = 3.
- Square both sides: x + 3 = 9.
- Subtract 3: x = 6.
Rational Equations
Example 8: Solve 4/(x - 5) = 3/x
- Objective: Remove the fractions.
- Steps:
- Cross multiply: 4x = 3(x - 5).
- Simplify and solve: x = -5.
Change of Subject (Transposing Formulas)
Example 9: Solve for x in y = mx + b
- Objective: Isolate x.
- Steps:
- Subtract b from both sides: y - b = mx.
- Divide by m: x = (y - b)/m.
Inequalities
Example 10: Solve -3x + 1 > 7
- Objective: Isolate x and note the change of the inequality sign when dividing by a negative number.
- Steps:
- Subtract 1 from both sides: -3x > 6.
- Divide by -3 (and flip inequality sign): x < -2.
Example 11: Solve -3 < x + 8 < 20
- Objective: Isolate x in a combined inequality.
- Steps:
- Subtract 8 from all parts: -11 < x < 12.
Graphing Inequalities
Example 12: Graph x > -4
- Steps:
- Locate -4 on the number line.
- Draw an unshaded circle at -4.
- Draw an arrow to the right to indicate x > -4.
Word Problems
Example 13: Packaging Gallons
- Problem: Ship 2500 gallons with 20 boxes and 100 gallons left over. Find gallons per box.
- Steps:
- Setup equation: 20x + 100 = 2500
- Subtract 100 then divide by 20: x = 120.
Example 14: Michael's Age
- Problem: 5 + 3 times Michael's age = 50. Find Michael's age.
- Steps:
- Setup equation: 5 + 3x = 50
- Subtract 5 then divide by 3: x = 15.
Functions vs Relations
Example 15: Identify non-functions
- Key points:
- No input value (x) should have multiple output values (y).
- Every input value must have an output value.
- Example that is not a function: An input 3 going to outputs 6 and 8.
Conclusion
- Happy Thanksgiving!
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