Self-Study Math

Algebra 1 & Geometry 1

Core problems with memory tips. Type your answer — no special symbols needed.

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Algebra 1
Linear Equations & Expressions
10 core problems · Enter numbers only · No fractions or symbols
A-01
Solving Linear Equations
Solve for \(x\):
\[3x + 7 = 22\]
MOVE & DIVIDE — move numbers first, then divide
📖 Example
Solve \(2x + 5 = 13\)
Step 1: subtract 5 → \(2x = 8\)
Step 2: divide by 2 → \(x = 4\)
\(x\) =
A-02
Two-Step Equations · Tricky Negative
Solve for \(x\):
\[5x - 3 = 2x + 12\]
COLLECT — collect x on one side, numbers on the other
📖 Example
\(4x - 1 = x + 8\)
→ \(3x = 9\) → \(x = 3\)
\(x\) =
A-03
Distributive Property · Most Missed
Solve for \(x\):
\[2(x + 4) = 18\]
DISTRIBUTE FIRST — multiply before solving
📖 Example
\(3(x - 2) = 12\)
→ \(3x - 6 = 12\) → \(3x = 18\) → \(x = 6\)
\(x\) =
A-04
Slope of a Line · Often Confused
Find the slope of the line passing through \((2, 3)\) and \((6, 11)\).
RISE over RUN — slope = (y2-y1)/(x2-x1)
📖 Example
Points \((1,2)\) and \((3,8)\):
slope \(= \dfrac{8-2}{3-1} = \dfrac{6}{2} = 3\)
slope =
A-05
y-intercept from Slope-Intercept Form
What is the y-intercept of the line \(y = 4x - 7\)?
Enter the y-intercept value only.
y = mx + b → b IS the y-intercept
📖 Example
\(y = 3x + 5\) → y-intercept is \(5\) (where the line crosses the y-axis)
b =
A-06
Systems of Equations · Substitution
Solve the system. Find \(x\):
\[\begin{cases} y = 2x \\ x + y = 9 \end{cases}\]
PLUG IN — substitute the first equation into the second
📖 Example
\(y = x + 1,\quad x + y = 5\)
→ \(x + (x+1) = 5\) → \(2x = 4\) → \(x = 2\)
\(x\) =
A-07
Exponent Rules · Classic Trap
Simplify: \(x^3 \cdot x^4\)
What is the exponent of \(x\)?
SAME BASE ADD exponents (x^a · x^b = x^(a+b))
📖 Example
\(x^2 \cdot x^5 = x^{2+5} = x^7\)   exponent = 7
exponent =
A-08
Factoring · Difference of Squares
Factor: \(x^2 - 25\)
What is the positive root? (the positive value that makes it zero)
A^2 - B^2 = (A+B)(A-B) → roots are +B and -B
📖 Example
\(x^2 - 16 = (x+4)(x-4)\) → positive root = 4
positive root =
A-09
Inequalities · Sign Flip Trap!
Solve: \(-2x > 8\)
What is \(x\)? (enter the boundary number, e.g. enter -4 if x < -4)
FLIP the sign when DIVIDING by NEGATIVE
📖 Example
\(-3x > 9\) → divide by -3, FLIP: \(x < -3\) → boundary = -3
boundary =
A-10
Quadratic · Find the Vertex x-value
For \(y = x^2 - 6x + 8\), what is the x-coordinate of the vertex?
VERTEX x = -b divided by 2a (for y = ax^2 + bx + c)
📖 Example
\(y = x^2 - 4x + 3\): a=1, b=-4 → vertex x = \(-\frac{-4}{2(1)} = 2\)
vertex x =
Geometry 1
Angles, Triangles & Circles
10 core problems · Enter numbers only · No degree symbols
G-01
Supplementary Angles
Two angles are supplementary. One angle is 65°. What is the other angle?
SUPPLEMENTARY = 180 (straight line)
📖 Example
One angle = 40° → other = 180 - 40 = 140°
angle =
G-02
Triangle Angles · Most Missed
A triangle has angles 55° and 80°. What is the third angle?
TRIANGLE SUM = 180 always
📖 Example
Angles 60° and 70° → third = 180 - 60 - 70 = 50°
third angle =
G-03
Pythagorean Theorem · Classic
A right triangle has legs 3 and 4. What is the hypotenuse?
a^2 + b^2 = c^2 → memorize 3-4-5 triangle
📖 Example
Legs 5 and 12 → \(5^2 + 12^2 = 25 + 144 = 169\) → hypotenuse = 13
hypotenuse =
G-04
Area of Triangle
A triangle has base 10 and height 6. What is the area?
HALF base times height — Area = (1/2) x b x h
📖 Example
Base = 8, height = 5 → Area = (1/2)(8)(5) = 20
area =
G-05
Vertical Angles · Tricky
Two lines intersect. One angle is 72°. What is the vertical (opposite) angle?
VERTICAL = EQUAL — opposite angles are always equal
📖 Example
Angle = 55° → vertical angle = 55° (same value, across the intersection)
vertical angle =
G-06
Circle — Circumference
A circle has diameter 10. What is the circumference?
Use π ≈ 3.14 and round to the nearest whole number.
C = pi x d (diameter) OR 2 x pi x r (radius)
📖 Example
Diameter = 5 → C = 3.14 × 5 = 15.7 → rounded ≈ 16
C ≈
G-07
Exterior Angle Theorem · Confused Often
An exterior angle of a triangle is 120°. Two interior angles are 70° and \(x\). Find \(x\).
EXTERIOR = SUM of 2 non-adjacent interior angles
📖 Example
Exterior = 100°, one interior = 60° → other = 100 - 60 = 40°
\(x\) =
G-08
Area of Circle
A circle has radius 7. What is the area?
Use π ≈ 3.14 and round to the nearest whole number.
Area = pi x r^2 (r squared, not diameter!)
📖 Example
Radius = 3 → Area = 3.14 × 9 = 28.26 ≈ 28
Area ≈
G-09
Parallel Lines — Alternate Interior Angles
Two parallel lines are cut by a transversal. One alternate interior angle is 58°. What is the other alternate interior angle?
ALTERNATE INTERIOR = EQUAL (Z-shape between parallel lines)
📖 Example
Alternate interior angle = 45° → the other alternate interior angle = 45°
angle =
G-10
Similar Triangles · Ratio Trap
Two similar triangles have corresponding sides in ratio 1:3. The smaller triangle's side is 4. What is the corresponding side of the larger triangle?
SIMILAR = PROPORTIONAL — multiply by the scale factor
📖 Example
Ratio 1:2, small side = 5 → large side = 5 × 2 = 10
large side =