Stand Up & Math · Grade 9 · Activity

The Quadratic in Disguise

Hidden quadratics · Exponential equations · Groups of 3–4 · Whiteboard
⏱ ~45–50 min 👥 Groups of 3–4 Grade 9 · Advanced 🖊 Work on your whiteboard
🎭 The Disguise

This equation — \(4^x - 5(2^x) + 4 = 0\) — doesn't look like anything you already know how to solve. But it's wearing a disguise. Can your group unmask it?

1

Spot the Disguise

Rewriting \(4^x\) in terms of \(2^x\)
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Task 1a — Rewrite the base

Using your laws of exponents, rewrite \(4^x\) so that it's written in terms of \(2^x\).

Task 1b — Look closely

Substitute your result from Task 1a back into the original equation, replacing \(4^x\). What do you notice about the equation now?

Task 1c — Make your move

Can your group turn this into an equation you already know how to solve? Show exactly what you did.

Task 1d — Name it

What kind of equation did you end up with?

🔐 Show your teacher to unlock Phase 2
2

Unmask It

Solving the hidden quadratic
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Complete Phase 1 and get the code from your teacher.

3

A Trickier Disguise

When a root has to be rejected
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Complete Phase 2 and get the code from your teacher.

4

The Impossible Case

Proving no solution exists
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Complete Phase 3 and get the code from your teacher.

🎭

Fully Unmasked!

You've worked through all four phases of The Quadratic in Disguise.
Well done — get ready for the class consolidation.