# Expression of a variable from formula - examples - page 9

- Bookshelve

Bookshelve with an original price of € 200 twice become cheaper. After the second discounted by 15% the price was € 149.60. Determine how much % become cheaper for the first time. - Rhombus and diagonals

The a rhombus area is 150 cm^{2}and the ratio of the diagonals is 3:4. Calculate the length of its height. - Cube wall

The perimeter of one cube wall is 120 meters. Calculate the surface area and the body diagonal of this cube. - On the farm

On the farm were housed 70 heads of cattle with food supply for 180 days. After 60 days, 10 head of cattle sold, and for the next 30 days they sold 10 more. How many days is sufficient supply of feed for the remaining cattle? - The deposit

Deposit has been placed for one year at an annual rate of 4.5%. After the added interst amount rose to € 2,612.5. Determine initial deposit. - Trapezoid

How long are the trapezoid bases with area 24 cm^{2}and height 3 cm. One base is 3 times longer than the shorter. - Circle and rectangle

A rectangle with sides of 11.7 cm and 175 mm is described by circle. What is its length? Calculate the content area of the circle described by this circle. - Isosceles trapezoid

Calculate the content of an isosceles trapezoid whose bases are at ratio 5:3, the arm is 6cm long and it is 4cm high. - Brigade

On a weekly forest brigade operates 12 students. After plant one hundred spruces get x CZK, anfter one hundred pines y CZK. How many CZK got one student for one day if planted spruces 25000 and 30000 pines week? - Prism bases

Volume perpendicular quadrilateral prism is 360 cm^{3}. The edges of the base and height of the prism are in the ratio 5:4:2 Determine the area of the base and walls of the prism. - Outer angles

The outer angle of the triangle ABC at the A vertex is 71°40 ' outer angle at the vertx B is 136°50'. What size has the inner triangle angle at the vertex C? - Surface area of cylinder

Determine the lateral surface of the rotary cylinder which is circumscribed cube with edge length 5 cm. - Prism

Calculate the height of the prism having a surface area 448.88 dm² wherein the base is square with a side of 6.2 dm. What will be its volume in hectoliters? - Painters

Five painters painting the fence for eight days. How many days over will take work if paint the fence only four decorators? - Rectangle from string

String 12m. Make rectangle when one side is two times longer than its width. - Cuboid and eq2

Calculate the volume of cuboid with square base and height 6 cm if the surface area is 48 cm^{2}. - Inscribed circle

XYZ is right triangle with right angle at the vertex X that has inscribed circle with a radius 5 cm. Determine area of the triangle XYZ if XZ = 14 cm. - Rhumbline

Find circumference and area of the rhumbline ABCD if the short side AD of which has a length of 5 cm, and the heel of the height from D leading to the AB side divides the AB side into two sections of 3 cm and 4 cm. - Ethnicity

Share of ethnicity XY is 26%, which is 1/9 more than in the prewar period. What was the share of that ethnicity in the pre-war period? - Tripled square

If you tripled the length of the sides of the square ABCD you increases its content by 200 cm^{2}. How long is the side of the square ABCD?

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