Answer: 14 weeks
Step-by-step explanation:
Given
Kadin wants to buy a laptop of [tex]\$500[/tex]
He already saved [tex]\$80[/tex] and started saving [tex]\$30[/tex] each week
Suppose he saves for [tex]x[/tex] weeks to get the laptop i.e.
[tex]\Rightarrow 500=80+30x\\\Rightarrow 420=30x\\\Rightarrow x=14\ \text{weeks}[/tex]
So, he need to save for 14 weeks to buy the laptop