President's 5862

For the opening ball of the season, the president's wife bought a necklace with a bracelet for 768 euros. How much did the necklace cost, and how much did the bracelet cost if the bracelet was 40% off

a) cheaper,
b) more expensive than the necklace?

Correct answer:

a =  448
b =  320
c =  320
d =  448

Step-by-step explanation:


a+b = 768
a = b + 40/100 b
c+d = 768
d = c + 40/100 c

a+b = 768
a = b + 40/100·b
c+d = 768
d = c + 40/100·c

a+b = 768
100a-140b = 0
c+d = 768
140c-100d = 0

Pivot: Row 1 ↔ Row 2
100a-140b = 0
a+b = 768
c+d = 768
140c-100d = 0

Row 2 - 1/100 · Row 1 → Row 2
100a-140b = 0
2.4b = 768
c+d = 768
140c-100d = 0

Pivot: Row 3 ↔ Row 4
100a-140b = 0
2.4b = 768
140c-100d = 0
c+d = 768

Row 4 - 1/140 · Row 3 → Row 4
100a-140b = 0
2.4b = 768
140c-100d = 0
1.7143d = 768


d = 768/1.71428571 = 448
c = 0+100d/140 = 0+100 · 448/140 = 320
b = 768/2.4 = 320
a = 0+140b/100 = 0+140 · 320/100 = 448

a = 448
b = 320
c = 320
d = 448

Our linear equations calculator calculates it.



Did you find an error or inaccuracy? Feel free to write us. Thank you!







Tips for related online calculators
Our percentage calculator will help you quickly calculate various typical tasks with percentages.
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: