Question

Spot the mistake:
$(3y+8{)}^2=9y^2+24y+64$

• A. 24y should be replaced by 48y
• B. 64 should be replaced by -64
• C. $9y^2$ should be replaced by $3y^2$
• D. There is no mistake in the given equation.

Answer 1

The correct option is A

24y should be replaced by 48y

$(3y+8{)}^2=9y^2+2\times 3y\times 8+64$
$=9y^2+48y+64$
Therefore, 24y is the wrong term. It should be replaced by 48y.