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Mixed practice

Expressions and structure

Try these fresh problems without your notes. Explain your method before opening a solution. This practice is not a graded school assessment.

Check 1

Evaluate 2³ + 3 × 4.

Check 2

Which expression is equivalent to 2(a + 5) + 3a?

Challenge 1

A museum charges $6 per child and $9 per adult. Write an expression for c children and a adults; evaluate it for c = 8 and a = 3.

Show a hint

Multiply each group count by its own ticket price, then add.

Show the worked solution

6c + 9a; $75.

For eight children and three adults, 6 × 8 + 9 × 3 = 48 + 27 = 75. The two variables represent different counts.

Revisit the related lesson

Challenge 2

A learner says 4(x + 2) = 4x + 2 because it works when x = 0. Evaluate both sides at zero, then correct and justify the identity.

Show a hint

Check the claimed evidence before using distribution.

Show the worked solution

At x = 0 the sides are 8 and 2, so the claim is false. The correct identity is 4(x + 2) = 4x + 8.

Distribution multiplies both x and 2 by four. A claimed matching input must actually be checked; even a genuine match at one input would not prove an identity.

Revisit the related lesson

Decide what to revisit

If a method was difficult to explain, return to that lesson and schedule a recall check. Unit-review answers are not saved as a score.

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