Question

Jackson bought a book for $\$10$ and 5 pens. He spent a total of $\$85$. Find the cost of each pen?
$

Answer 1

Cost of a book $=\$10$
Let the cost of each pen be $\$x$
Total cost of 5 books $=\$x\times 5=\$5x$

Total money spent $=\$85$
Cost of of book + Total cost of 5 pens = Total money spent
$\Rightarrow 10+5x=85$

Step 1: Subtract 10 from both sides of the equation to eliminate the constant on the left side of the equation.
$10+5x-10=85-105x=75$

Step 2: Now, divide both sides by 5 to eliminate 5 on the left side of the equation.
$\frac{5x}{5}=\frac{75}{5}x=15$

Hence, cost of each pen is $\$15.$