Examples of linear equations
Example 1.
Example 2.
Example 3.
Example 4.
The price of a product was raised by 16% and the new increased price was 754 euros. What was the price before the raise?
The original price is unknown, so let us mark it with x. That price was raised by 16%, so the raise in euros is .
The new price is the original price plus the raise, so
The price before the raise was 650 euros.
Example 5.
A carpet is in sale. The price of the carpet is 39 euros and it is said that price is decreased by 43%. What was the original price of this carpet?
The original price is unknown, so let us mark it with x. That price was decreased by 43%, so the decrease in euros is .
The new price is the original price minus the decrease, so
The price before the decrease was about 68 euros.
Example 6.
You paid 35 € for a hair cut. How much of it stays at hairdresser's?
The price with VAT consists of the price without VAT + VAT. As the price without VAT is unknown, we can mark it with x. VAT in Finland for hairdresser's services is 24%. Thus,
Example 7.
You have noticed that you need 1500 euros for living in a month. Your Finnish personal scale of taxation says, that you have to pay 15% tax till 900 euros and, after that, 27%. How much should your monthly salary be so that you earn 1500 euros at least?
Your monthly salary is unknown x. As you must earn more than 900 euros, you have to pay 27% of part exceeding 900 euros. Thus, your net salary is
So, you should earn about 2170 euros per month.