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Algebra Basics Review

In this review lesson you’ll revisit the major ideas from Algebra Basics, practice mixed problems across topics, and apply them to real-life situations to solidify your skills before moving to the next section.

Algebra Basics builds on Pre-Algebra by focusing on linear relationships and early polynomials. Key skills include:

  • Solving multi-step equations and inequalities (including variables on both sides)
  • Rearranging literal equations and formulas
  • Understanding functions, slope, and linear forms (slope-intercept, point-slope, standard)
  • Graphing lines and solving systems (graphing, substitution, elimination)
  • Working with polynomials (adding, subtracting, basic factoring)

Tips for mixed review:

  • Identify the main concept first (equation, system, factoring, etc.)
  • Show all steps, especially when solving systems or factoring
  • Check solutions by substituting back or estimating
  • Use real-world context to verify answers make sense

1. Solve the system:

{2x+3y=12xy=1\begin{cases} 2x + 3y = 12 \\ x - y = 1 \end{cases}

Use substitution. Solve the second equation for x:

x=y+1x = y + 1

Substitute into the first equation:

2(y+1)+3y=122y+2+3y=125y=10y=2\begin{aligned} 2(y + 1) + 3y &= 12 \\[1em] 2y + 2 + 3y &= 12 \\[1em] 5y &= 10 \\[1em] y &= 2 \end{aligned}

Back-substitute to find x:

x=2+1=3x = 2 + 1 = 3

Solution: (3,2)(3, 2)

2. Factor x² + 6x + 8

Find two numbers that multiply to 8 and add to 6: that’s 4 and 2.

x2+6x+8=(x+4)(x+2)x^2 + 6x + 8 = (x + 4)(x + 2)

Check (FOIL): (x+4)(x+2)=x2+2x+4x+8=x2+6x+8(x + 4)(x + 2) = x^2 + 2x + 4x + 8 = x^2 + 6x + 8

3. Solve 5x − 7 = 3(x + 2)

5x7=3x+65x3x=6+72x=13x=132=6.5\begin{aligned} 5x - 7 &= 3x + 6 \\[1em] 5x - 3x &= 6 + 7 \\[1em] 2x &= 13 \\[1em] x &= \frac{13}{2} = 6.5 \end{aligned}

4. Evaluate f(x) = 2x² − 3x + 1 when x = −1

f(1)=2(1)23(1)+1=2(1)+3+1=6\begin{aligned} f(-1) &= 2(-1)^2 - 3(-1) + 1 \\[1em] &= 2(1) + 3 + 1 \\[1em] &= 6 \end{aligned}

Algebra Basics skills solve practical problems:

  • Budget comparison: Two plans. Plan A: 45+0.12x45 + 0.12x, Plan B: 60+0.08x60 + 0.08x. When are they equal?

    45+0.12x=60+0.08x0.04x=15x=375 units\begin{aligned} 45 + 0.12x &= 60 + 0.08x \\[1em] 0.04x &= 15 \\[1em] x &= 375 \text{ units} \end{aligned}

  • Area modeling: A room’s area is x2+8x+15x^2 + 8x + 15 square feet. Factor to find dimensions:

    x2+8x+15=(x+3)(x+5)x^2 + 8x + 15 = (x + 3)(x + 5)

    So the room is (x+3)(x + 3) by (x+5)(x + 5) feet.

  • Work rates: Job A pays 20 dollars/hour. Job B pays 15 dollars/hour plus a 100-dollar bonus. When does total pay match?

    20h=15h+1005h=100h=20 hours\begin{aligned} 20h &= 15h + 100 \\[1em] 5h &= 100 \\[1em] h &= 20 \text{ hours} \end{aligned}

These tools help compare costs, model areas and profits, and plan work or budgets.

Solve $4x + 5 = 2x + 17$.
Factor $x^2 - 5x - 14$.
A line has slope 3 and passes through $(1, 4)$. Which point-slope equation?
Solve the system: $y = x + 2$ and $3x + y = 14$.
What is the slope of the line through $(2, 5)$ and $(6, 13)$?
Factor $x^2 + 7x + 12$.
Solve $5x - 3 = 2x + 9$.
What is the y-intercept of $y = -2x + 8$?
Simplify $3(2x - 4) + 5x$.
Solve the system: $2x + y = 10$ and $x - y = 2$.
Factor $x^2 - 9$.
For $f(x) = 2x - 7$, what is $f(5)$?
Solve $-4x + 1 > 13$.
What is the degree of $5x^3 - 2x + 8$?
A line passes through $(0, -3)$ with slope $2$. Write the equation.
Add $(3x^2 + 2x - 1) + (x^2 - 5x + 4)$.
Solve $\frac{x + 2}{3} = 5$.
Two numbers add to 30 and differ by 8. What are they?
A horizontal line has a slope of:
Factor completely: $3x^2 - 12$.