Algebra 1
Algebra
Linear equations and functions, systems, exponents, polynomials, factoring, quadratics, radicals and rational expressions — the toolkit every later course assumes.
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The Toolkit
Unit 1 · Foundations
0 of 11 units complete
- 1Unit 1Foundations5 parts · about 11 min
The Toolkit
Before algebra takes off: the families of real numbers, absolute value, sign rules, the order of operations, and the properties that let you rearrange anything. Plus a proof that 1 = 2 (spot the flaw).
- 2Unit 2Equations & Inequalities5 parts · about 12 min
Equations That Fight Back
Multi-step equations, variables on both sides, fractions, formulas solved for any letter, equations with no solution or every solution, and inequalities that flip.
- 3Unit 3Linear Equations & Functions5 parts · about 13 min
Lines and Functions
A function is a machine with one output per input. Meet slope as steepness, drive the line y = mx + b with sliders, write lines through points, and find perpendicular lines by flipping a fraction.
- 4Unit 4Systems of Equations5 parts · about 11 min
Where Lines Meet
Two equations, two unknowns. Solve by graphing, substitution and elimination, find when there is no answer or infinitely many, and crack the classic tickets-and-chickens puzzles.
- 5Unit 5Exponents5 parts · about 15 min
The Power of Powers
Every exponent rule is just counting factors. Learn them once, simplify anything, write the size of the universe, and watch exponential growth leave every straight line behind.
- 6Unit 6Polynomials5 parts · about 15 min
Polynomials as Rectangles
Add and subtract polynomials by collecting like terms, then multiply them with algebra tiles until FOIL becomes obvious. Special products, and a mental-math trick for squaring numbers ending in 5.
- 7Unit 7Factoring5 parts · about 13 min
Taking Things Apart
Factoring is multiplying backwards. Pull out common factors, find the rectangle hiding in a trinomial, spot differences of squares, and use the zero product property to solve equations.
- 8Unit 8Quadratics5 parts · about 12 min
Parabolas
The graph of every quadratic is a parabola. Drive one with sliders, find where it crosses zero, solve any quadratic with the formula, and predict how many solutions there are before solving.
- 9Unit 9Radicals5 parts · about 13 min
Roots and Radicals
Estimate square roots on the number line, simplify radicals by pulling out perfect squares, rationalise denominators, use Pythagoras on a grid, and catch the extraneous solution.
- 10Unit 10Rational Expressions5 parts · about 11 min
Fractions with x in Them
Rational expressions are fractions of polynomials. Find the values that break them, simplify by cancelling factors (never terms), add with common denominators, and solve the classic two-painters problem.
- 11Unit 11Data & Statistics5 parts · about 12 min
Making Sense of Data
Summarise data with five numbers and a box plot, describe shapes, fit a line through a cloud of points by eye, and learn the most important sentence in statistics: correlation is not causation.