Question

Circle describe and correct each error 5r^2-6r=-15r^2-6r+1=0(R+1)(5r+1)=0R+1=0 and 5r+1=0R=-1 and b=1-/5

Answer 1

Explanations:

Given the equation

$5r^2-6r=-1$

Add 1 to both sides

$\begin{gathered} 5r^2-6r+1=-1+1 \\ 5r^2-6r+1=0 \end{gathered}$

Factorize the result

$\begin{gathered} 5r^2-5r-r+1=0 \\ 5r(r-1)-1(r-1)=0 \\ (r-1)(5r-1)=0 \end{gathered}$

Error 1

According to the calculation in question, you can see that one of the errors made in the calculation is factorizing wrongly. The factors of the expression are (r-1) and (5r-1) instead of (r+1) and (5r+1)

Determine the zeros of the equation

$\begin{gathered} (r-1)(5r-1)=0 \\ r-1=0\text{ and }5r-1=0 \\ r=1\text{ and }r=\frac{1}{5} \end{gathered}$

Error 2:

The solutions shown in question are incorrect. The correct solution are 1 and 1/5