GCSE Secondary Maths Age 13-17 - Algebra: Algebra - Explained

The video tutorial discusses common mistakes made by students when solving equations. Steve's mistake involves incorrect expansion of brackets, while Liz's error is not considering both positive and negative solutions when taking the square root. The instructor advises reworking problems independently to better identify errors.

What was Steve's error when expanding the equation 5(X + 2) = 47?

• He subtracted 2 instead of adding.

• He did not multiply 5 by 2.

• He forgot to multiply 5 by X.

• He added 2 instead of multiplying.

What is the correct first step in solving the equation 3X^2 + 8 = 83?

• Divide both sides by 3.

• Add 8 to both sides.

• Multiply both sides by 3.

• Subtract 8 from both sides.

What mistake did Liz make when solving for X in the equation 3X^2 = 75?

• She forgot to square the result.

• She did not divide by 3.

• She only considered the positive square root.

• She added 8 instead of subtracting.

When taking the square root of a number, what should you remember?

• Only the positive value is valid.

• Neither value is valid.

• Only the negative value is valid.

• Both positive and negative values are valid.

What is a useful strategy for identifying mistakes in a friend's math solution?

• Rely on their calculations.

• Rework the problem independently.

• Ask someone else to solve it.

• Ignore the problem.