Algebraic expressions
An expression is simplified by collecting like terms: the x's with the x's and the numbers with the numbers. A squared bracket expands: (x + 3)² = x² + 6x + 9, with the double product in the middle. Taking out a common factor is reading that backwards: 6x + 9 = 3(2x + 3).
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Exercises from this rung
Generated by the app, from easiest to hardest
If x = 2, what is 3x + 1?
Answer 7
Why 3 × (2) + 1 = 6 + 1 = 7.
easierIf x = −2, what is x² + 2?
Answer 6
Why (−2)² + 2 = 4 + 2 = 6. The square of a negative is positive.
in between3x + 2 + 5x + 2
- 15x + 4
- 8x
- 8x + 4
- 12x
Why The x's: 3 + 5 = 8. The numbers: 2 + 2 = 4. That leaves 8x + 4.
harder