Hugo decided to pay [tex]$\$[/tex]2$ a week to his brother to buy a bicycle. The equation [tex]y - 10 = -2(x - 10)[/tex] models the amount of money he owes for the bike, where [tex]x[/tex] is the number of weeks and [tex]y[/tex] is the amount of money he still needs to pay.

1. How much did the bicycle cost? [tex]\$[/tex]

2. After how many weeks will Hugo finish paying for the bike? [tex] \text{weeks}[/tex]



Answer :

To solve the problem, we will go through the following steps:

1. Rearrange the equation to find the initial cost of the bicycle:
The given equation is:
[tex]\[ y - 10 = -2(x - 10) \][/tex]
We will rearrange this equation to the slope-intercept form [tex]\( y = mx + b \)[/tex].

Start by distributing the [tex]\(-2\)[/tex] on the right-hand side:
[tex]\[ y - 10 = -2x + 20 \][/tex]
Now, add 10 to both sides to isolate [tex]\(y\)[/tex]:
[tex]\[ y = -2x + 20 + 10 \][/tex]
Simplify the equation:
[tex]\[ y = -2x + 30 \][/tex]

2. Determine the initial cost of the bicycle:
When Hugo starts paying, the number of weeks [tex]\(x\)[/tex] is 0. Substitute [tex]\(x = 0\)[/tex] into the equation to find [tex]\(y\)[/tex]:
[tex]\[ y = -2(0) + 30 \][/tex]
[tex]\[ y = 30 \][/tex]
Therefore, the initial cost of the bicycle is \[tex]$30. 3. Calculate the number of weeks Hugo will take to finish paying for the bike: To determine this, we need to find out after how many weeks \(x\) the amount of money owed, \(y\), becomes zero. Set \(y = 0\) and solve for \(x\): \[ 0 = -2x + 30 \] Subtract 30 from both sides: \[ -30 = -2x \] Divide both sides by -2: \[ x = 15 \] Hence, Hugo will finish paying for the bicycle after 15 weeks. To summarize: - The cost of the bicycle is \(\$[/tex]30\).
- Hugo will finish paying for the bike in 15 weeks.