Peta attempted to solve the following equation. Explain Peta's error.

Question

x (x - 5) = 20
x = 20 and x - 5 = 20
x = 20 and x = 25

Answer 1

Peta needs to get tutoring from her brother in college.

She is setting the function
a*b=n and assuming a is equal to n or b is equal to n, that would only occur if the other factor is one, and there is no reason to believe that.

only in the instance of
ab=0 can one assume a is zero, or b is zero, or both are zero.

Answer 2

only in the instance of
ab=0 can one assume a is zero, or b is zero, or both are zero.

Answer 3

Peta can only use the zero product property when the product of factors is equal to zero.

Peta must multiply x by (x - 5).

Peta must write the equation in standard form, then factor the expression.

Each factor must be set equal to zero, not 20.

Answer 4

Peta can only use the zero product property when the product of factors is equal to zero.

Peta must multiply x by (x - 5).

Peta must write the equation in standard form, then factor the expression.

Each factor must be set equal to zero, not 20.