3rd Periodical Exam Math 9.docx

Republic of the Philippines DEPARTMENT OF EDUCATION Florita Herrera - Irizari National High School Lanuza, Surigao del Sur

3rd PERIODICAL EXAMINATION MATHEMATICS 9 Name: ___________________________________________

Score: ______________

Direction: Encircle the letter that you think is the best answer to each question. Show your solution on the separate sheet of paper to questions that need solutions. 1. The cost c varies directly as the number n of pencils is written as a. c=kn b. k=cn c. n=k/c d. c=k/n 2. A car travels a distance of d km in t hours. The formula that relates d to t is d=kt. What kind of variation is it? a. direct b. inverse c. joint d. combined 3. What is the formula suited for the statement “z varies directly as x and inversely as y”? a. x=kz/y b. z=kx/y c. k=zx/y d. z=kxy 4. y varies directly as x and y = 32 when x= 4. Find the constant of variation. a. 8 b. 36 c. 28 d. 128 2 5. If h varies jointly as j and i inversely as g, and h=50 when j=2, i= 5, and g=1/2, find h when j=4, i=10, and g=1/4 a. 25 b. 100 c. 800 d. 805 6. What would be the result if 1,200,200 is raised to zero? a. 1,200,2000 b. 0 c. 1 d. undefined 0 7. Simplify 2a 2b  a. 2ab b. 2a c. 4ab d. 1 0 0 8. 2a 2b  is added to s 2t 4  , the result would be a. 0 b. 1 c. 2 d. 2abst 9. “When dividing powers with same base, keep the base and add the exponents”, the statement is a. always true b. sometimes true c. always wrong d. sometimes wrong 10. z varies jointly as x and y. If z= 10, when x =5 and y=6, find the constant of variation. a. 2/3 b. 3/2 c. 4/6 d. 8/12 11. An expression with a negative exponent CANNOT be written as an expression with positive exponent. a. always true 5 8 b. sometimes true c. always wrong d. sometimes wrong 12. Simplify 36a4 b5 4a b a. 9ab3 b. 9a3 c. 9ab2 d. 9a4 13. Which is an example of a direct variation? a. xy = 10 b. y = 2/x c. y = 5x d. 2/y = x 14. If y varies ineversely as x and y =1/3 when x = 8, find y when x is -4. a. -2/3 b. 2/3 c. -32/3 d. 32/3 15. If (x-4) varies inversely as (y+3) and x = 8 when y = 2, find x when y =-1. a. 20 b. 18 c. 16 d. 14 II. Solve the following.(Show your solution) 16-20. Simplify 21-28. p varies directly as q and the square of r and inversely as s. a. Write the equation of the relation b. find k if p=40 when q=5, r=4 and s=6 c. find p when q=8, r=6 and s=9 d. find s when p=10, q=5 and r=2 29-35. Add 1441/2, 1691/2, – (49)1/2 and 2163 36-40. Simplify 1 with positive exponent (x+10)-1/2