# Expression of a variable from formula - examples - page 16

- Rectangular triangle PQR

In the rectangular triangle PQR, the PQ leg is divided by the X point into two segments of which longer is 25cm long. The second leg PR has a length 16 cm. The length of the RX is 20 cm. Calculate the length p of side RQ. The result is round to 2 decimal - Diagonal of square

Calculate the side of a square when its diagonal is 10 cm. - Determine AP

Determine the difference of the arithmetic progression if a3 = 7, and a4 + a5 = 71 - Geometric seq

Find the third member of geometric progression if a1 + a2 = 36 and a1 + a3 = 90. Calculate its quotient. - Diagonals

Given a rhombus ABCD with a diagonalsl length of 8 cm and 12 cm. Calculate the side length and content of the rhombus. - Red balls

In the bag there are 3 red, 12 blue and 8 green balls. How many red balls we must be attached to the bag if we want the probability of pulling out the red balls was 20%? - Two machines

Performances of two machines are in a ratio of 7:12. A machine with less power produced 406 pieces of products per shift. a) How many pieces produced per shift second machine? b) How many pieces produced two machines together for five shifts? - Quotient

Determine the quotient and the second member of the geometric progression where a3=10, a1+a2=-1,6 a1-a2=2,4. - Coach

Average age of 24 players and a coach of one team is 24 years. The average age of players without a coach is 23 years. How old is the coach? - Hotel

The hotel has a p floors each floor has i rooms from which the third are single and the others are double. Represents the number of beds in hotel. - Q of GP

Calculate quotient of geometric progression if a1=5 a a1+a2=12. - Chord

It is given to a circle k(r=6 cm) and the points A, B such that / AB / = 8 cm lies on k. Calculate the distance of the center of circle S to the midpoint C of the segment AB. - Ratio iso triangle

The ratio of the sides of an isosceles triangle is 7:6:7 Find the base angle to the nearest answer correct to 3 significant figure. - Coefficient

Determine the coefficient of this sequence: 7.2; 2.4; 0.8 - Parallelogram

Calculate the missing side of a parallelogram, if you know the perimeter o and one side: a) o = 7.2 cm; b = 1.8 cm b) o = 5.4 cm; a = 1.9 cm - Difference AP 4

Calculate the difference of the AP if a1 = 0.5, a2 + a3 = -1.1 - Right triangle eq2

Find the lengths of the sides and the angles in the right triangle. Given area S = 210 and perimeter o = 70. - Volume and area

What is the volume of a cube which has area of 361 cm^{2}? - Combinations

If the number of elements increase by 3, it increases the number of combinations of the second class of these elements 5 times. How many are the elements? - Boys and girls

There are 28 girls in the hall. 5/7 of all children are boys. How many children and how many boys are there?

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