Checkpoint: parts, joining and multiplying

What is the coefficient of the term −4b?

• `b`, because that is the part that can change
• 4, because the minus sign belongs to the letter
• −4

Four dates in a calendar square add to 4a + 16. What is the sum when a = 10?

• 26, because only one `a` is counted
• 56
• 416, because 4 and 16 are put side by side

What does 5a × 3a come to?

• `15a`, because the letters gather into one
• `15a²`
• `8a²`, because 5 and 3 are added

What does 3m(2m + 4) open out to?

• `6m² + 12m`
• `6m + 12m`, because `m × m` is written as `m`
• `6m² + 4`, because only the first term inside is reached

What does (x + 3)(x + 7) come to?

• `x² + 10x + 21`
• `x² + 10x`, because the last pairing is not a term with a letter
• `x² + 21`, because the firsts multiply and the lasts multiply