Grade 8 Expressions & Equations Practice — Easy

Question 1 of 26Score 0/0Easy

Question 1 of 26: Simplify: 3⁴ · 3².

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Keep going: Read the lesson: Properties of Integer Exponents Scientific Notation Exponent Rules
Answer key for parents & teachers (26 questions)
  1. Simplify: 3⁴ · 3².3⁶. Product rule: 3⁴ · 3² = 3^(4+2) = 3⁶ = 729.
  2. Evaluate: 5⁰.1. Any nonzero number raised to the power 0 equals 1: 5⁰ = 1.
  3. Simplify: 2⁻³.1/8. Negative exponent means reciprocal: 2⁻³ = 1/2³ = 1/8.
  4. Simplify: x⁶ / x².x⁴. Quotient rule: x⁶ / x² = x^(6−2) = x⁴.
  5. Simplify: (3²)³.3⁶. Power rule: (3²)³ = 3^(2×3) = 3⁶ = 729.
  6. Which is equivalent to 4⁻²?1/16. 4⁻² = 1/4² = 1/16.
  7. Which rule justifies: (aᵐ)ⁿ = aᵐⁿ?Power of a power rule. (aᵐ)ⁿ = aᵐⁿ is the power-of-a-power rule (multiply exponents when a power is raised to another power).
  8. What does a negative exponent tell you to do?Take the reciprocal of the base raised to the positive exponent. a⁻ⁿ = 1/aⁿ. The negative exponent means "move to the denominator and make the exponent positive."
  9. Simplify: x¹² / x¹².1 (= x⁰). x¹²/x¹² = x^(12−12) = x⁰ = 1.
  10. Write 4,500,000 in scientific notation.4.5 × 10⁶. Move the decimal 6 places to the left: 4.5 × 10⁶. The coefficient must be between 1 and 10.
  11. Write 0.0000072 in scientific notation.7.2 × 10⁻⁶. Move decimal 6 places right to get 7.2; since it is a small number, exponent is negative: 7.2 × 10⁻⁶.
  12. Convert 3.08 × 10⁴ to standard form.30,800. Move decimal 4 places right: 3.08 → 30,800.
  13. Convert 6.1 × 10⁻³ to standard form.0.0061. Negative exponent → move decimal left: 6.1 → 0.0061.
  14. Which number is written correctly in scientific notation?5.3 × 10⁴. Only 5.3 × 10⁴ has a coefficient between 1 and 10. The others violate the definition.
  15. Multiply: (2 × 10⁵) × (5 × 10³). Express in scientific notation.1.0 × 10⁹. 2 × 5 = 10, 10⁵ × 10³ = 10⁸. So 10 × 10⁸ = 1.0 × 10⁹.
  16. Divide: (9 × 10⁷) ÷ (3 × 10²). Express in scientific notation.3 × 10⁵. 9/3 = 3, 10⁷/10² = 10⁵. Result: 3 × 10⁵.
  17. Which exponent makes this true: 0.0045 = 4.5 × 10?10⁻³. Moving the decimal 3 places right gives 4.5 from 0.0045, so the exponent is −3.
  18. Which real-world quantity is best measured in scientific notation?The number of atoms in a grain of sand (~10²⁰). Scientific notation is most useful for extremely large or small quantities. A grain of sand contains roughly 10²⁰ atoms — far too large for standard notation.
  19. What is the slope of the line y = 4x − 3?4. In slope-intercept form y = mx + b, the slope is the coefficient of x. Here m = 4.
  20. What is the y-intercept of y = −2x + 7?7. In y = mx + b, b is the y-intercept. Here b = 7.
  21. Find the slope through (0, 3) and (2, 7).2. m = (7 − 3)/(2 − 0) = 4/2 = 2.
  22. A line has slope 0. What does its graph look like?A horizontal line. Slope 0 means no rise for any run — a perfectly horizontal line.
  23. What is the slope of a vertical line?Undefined. A vertical line has the same x for all y, so the run is 0. Division by zero is undefined.
  24. Write the equation of a line with slope 3 and y-intercept −1.y = 3x − 1. Substitute m = 3 and b = −1 into y = mx + b: y = 3x − 1.
  25. Which method is most efficient when one equation is already solved for a variable?Substitution. Substitution is most efficient when one equation is in the form y = … or x = … because you can directly substitute.
  26. In a system, the graphs of two lines intersect at (−2, 5). What is the solution?x = −2, y = 5. The solution of a system is the intersection point: (−2, 5), meaning x = −2 and y = 5.