To solve the equation [tex]\( y - 21 = 8y \)[/tex], follow these steps:
1. Isolate the variable term: We begin by getting all the terms containing [tex]\(y\)[/tex] on one side of the equation. Subtract [tex]\(y\)[/tex] from both sides:
[tex]\[
y - 21 - y = 8y - y
\][/tex]
2. Simplify both sides: On the left side, [tex]\( y - y \)[/tex] cancels out, leaving us with:
[tex]\[
-21 = 7y
\][/tex]
3. Solve for [tex]\(y\)[/tex]: To isolate [tex]\(y\)[/tex], divide both sides of the equation by 7:
[tex]\[
\frac{-21}{7} = \frac{7y}{7}
\][/tex]
4. Simplify the division:
[tex]\[
-3 = y
\][/tex]
Thus, the solution to the equation [tex]\( y - 21 = 8y \)[/tex] is [tex]\( y = -3 \)[/tex].
