Work through the levels in order. Type your answer and press Check — open the worked solution if you get stuck. Answers like -6, 3/4 or 0.25 are typed exactly as shown.
Level 1 · Warm-up
1 Simplify 4x + 3x. (as a simplified expression)
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Same species: 4 + 3 = 7x.
2 Simplify 9y − 2y. (as a simplified expression)
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9 − 2 = 7y.
3 Simplify 6a + 2 + 3a. (as a simplified expression)
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a-terms: 6a + 3a = 9a; the 2 has no partner: 9a + 2.
Level 2 · Core
4 Simplify 8p − 3 − 5p + 7. (as a simplified expression)
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p: 8 − 5 = 3; constants: −3 + 7 = 4 → 3p + 4.
5 Simplify 5m + 2n − m + 4n. (as a simplified expression)
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m: 5 − 1 = 4; n: 2 + 4 = 6 → 4m + 6n.
6 Simplify 4x2 + 3x − x2. (like 3x2+3x)
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x2-tribe: 4 − 1 = 3 → 3x2 + 3x. The x term is a different species.
Level 3 · Challenge
7 Simplify 7ab − 2a + 3ba − 5a. (as a simplified expression)
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ab-tribe (ba = ab): 7 + 3 = 10ab; a-tribe: −2 − 5 = −7a → 10ab − 7a.
8 A rectangle has length 3x + 2 and width x + 1. Perimeter? (as a simplified expression)
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2(3x+2) + 2(x+1) = 6x + 4 + 2x + 2 = 8x + 6.
9 Simplify 2x2 − 3x + 5 − x2 + 7x − 9. (like x2+4x-4)
Show worked solution
x2: 2 − 1 = 1; x: −3 + 7 = 4; constants: 5 − 9 = −4 → x2 + 4x − 4.