Equation + expression of a variable from the formula - math problems

Number of problems found: 260

  • A bottle
    flasa A bottle full of cola weighs 1,320 g. If we drink three-tenths of it, it will weigh 1,008g. How much does an empty bottle weigh?
  • Bike cost
    bicycle_gears The father gave his son € 100 to buy a bicycle, which was 40% of the total amount of the bicycle. How much did the bike cost?
  • Library
    books_1 New books were purchased for the library. Five-eighths were professional books, one-fifth were encyclopedias, and 231 books were dictionaries. How many professional books were there?
  • Double price reduction
    tv The price of TV has been reduced twice. First by 15% and later by another 10% of the reduced price. After this double price reduction, the TV was sold for 8,874 crowns. What was the original price of the TV?
  • Linear function
    runners Using one of the following forms x+p=q or px=q write an to represent these problems using x as the unknown variable Larry ran 7 more miles than Barry in a month, if Larry ran 20 miles how many did Barry run? please help its due tomorrow
  • The number 72
    percent_2 The number 72 increase by 25%. By how much % will you have to reduce the number you created to get the number 72 again?
  • Hectares of forest
    stromy 12 workers plant 24 ha of forest in 6 days. In how many days will 15 people and 12 people plant the same area?
  • In a
    triangles_1 In a triangle, the aspect ratio a: c is 3: 2 and a: b is 5: 4. The perimeter of the triangle is 74cm. Calculate the lengths of the individual sides.
  • The farmer
    cow The farmer calculated that the supply of fodder for his 20 cows was enough for 60 days. He decided to sell 2 cows and a third of the feed. How long will the feed for the rest of the peasant's herd last?
  • Second side
    rectangles2 Calculate the length of the other side of the rectangle if its circumference is 60 cm and one side is 10 cm long.
  • Railway embankment
    rr_lichobeznik The section of the railway embankment is an isosceles trapezoid, the sizes of the bases of which are in the ratio 5: 3. The arms have a length of 5 m and the height of the embankment is 4.8 m. Calculates the size of the embankment section area.
  • Vertical rod
    shadow The vertical one meter long rod casts a shadow 150 cm long. Calculate the height of a column whose shadow is 36 m long at the same time.
  • Area and perimeter of rectangle
    rectnagles The content area of the rectangle is 3000 cm2, one dimension is 10 cm larger than the other. Determine the perimeter of the rectangle.
  • Roots and coefficient
    parabola In the equation 2x ^ 2 + bx-9 = 0 is one root x1 = -3/2. Determine the second root and the coefficient b.
  • 1 page
    books 1 page is torn from the book. The sum of the page numbers of all the remaining pages is 15,000. What numbers did the pages have on the page that was torn from the book?
  • Water container
    cubes2 The cube-shaped container is filled to two-thirds of its height. If we pour 18 liters, it will be filled to three-fifths of the height. What is the volume of the whole container?
  • A map
    land_1 A map with a scale of 1: 5,000 shows a rectangular field with an area of 18 ha. The length of the field is three times its width. The area of the field on the map is 72 cm square. What is the actual length and width of the field?
  • Shell area cy
    valec The cylinder has a shell content of 300 cm square, while the height of the cylinder is 12 cm. Calculate the volume of this cylinder.
  • Find the 15
    ellipseTangent Find the tangent line of the ellipse 9 x2 + 16 y2 = 144 that has the slope k = -1
  • Lookout tower
    tower How high is the lookout tower? If each step was 3 cm lower, there would be 60 more of them on the lookout tower. If it was 3 cm higher again, it would be 40 less than it is now.

Do you have an interesting mathematical word problem that you can't solve it? Submit a math problem, and we can try to solve it.



We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...



Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?