M$A exam no. 2 Write answers on right. Problems are worth 5 points except as noted. 1) It is 50 degrees at sunrise. Then the temperature rises 25 degrees, falls 5 degrees, rises another 15, then falls 25. How warm is it now? 2) Maria weighs 100 pounds, Susie weighs 90, Josie weighs 120, Julie weighs 140. What is their average (mean) weight? 3) What is the median weight of the four girls? 4) Find as a proper fraction 5) Convert the result of the last problem to decimal notation. 6) Find the least common multiple of 13 and 17. 7) Evaluate the expression p + q for p = 9, q = -6 . 8) Bill has twice as much money as Julie. Write a legend for the situation. 9) A rectangle has a width of 15 and a length of 19 cm. What is its perimeter? 10) A pentagon has sides all equal to s. Write and expression for its perimeter in terms of s. 11) A hexagon has sides all equal to 2x - 1. Write an expression for its perimeter in terms of x. 12) Evaluate 3 x ^2 - 2 y for x = -2 and y = -1 13) Sam is 3 years younger than John. Write a legend. 14) Mary scored 70, 80, and 95 on three tests. If x denotes her score on the forth exam, write an equation for the mean (average) of her test scores, in terms of x. 15) Julie has three cats, tiger, ginger and tabbie. If tabbie weights the same as tiger, and ginger weighs 12 pounds, write an expression for the total weight of the three cats. Include a legend ! 16) Evaluate –5 x^2 –7 x + 3.4 for x = 0.7 and round the result to 1 digit after the decimal point. 17) (10 points) If Kyle would give 2 dollars to John, they would both have the same amount. But if instead John gave 2 dollars to Kyle, Kyle would have twice as much as John. How much do they have together? (Only a full explanation will be accepted, not just the result). 18) Write the rules of multiplication and division of signed numbers. 19) Write the rules of addition and subtraction of signed numbers. 20) Sketch an irregular hexagon with sides of eual length. 21) A carpenter can earn $11.50 per hour after he has made a one-time investment of $250 in tools. Write an equation (with legend!) expressing his profit as a function of the number of hours worked. 22) Find the mean (average) of 2x-6, 20, 2(6-x) 23) Find the median of 4, 2-x^2, 4.5 + 2(-x)^2, 2(3+x^2),-2(1+ x^2/2) 24) (10 points) Make a table of values (for x ranging from –2 to 2) and a graph for the expression y = -4x –3 .

50+25-5+15-25=60 (100+90+120+140)/4=112.5 (100+120)/2 = 110 13·17 = 221 9 + (-6) = 3 Julie: x, Bill: 2x 2(15+19)=68 cm 5s 6(2x-1)=12x-6 3 (-2)^2 –2(-1) = 3·4 + 2 = 14 John: x, Sam: x-3 (70+80+95+x)/4 = (245+x)/4 (12+2x)/3 where x = tabbie’s weight -5(0.7)^2 – 7(0.7) + 3.4 = -3.95 ~ -3.9 Kyle has 2+2=4 dollars more than John. Guess-and-test: 10 and 14. (10-2=8, 14+2=16 =2·8) . 10+14=24. Same signs: result positive, different signs: result negative Same signs: add, different signs: subtract. Result has sign of the number with the largest absolute value.. Y = 11.5 X - 250 where Y = profit, X = number of hours worked. (2x-6+20+12-2x)/3 = 26/3 = 8 2/3 4 because -2-x^2 < 2-x^2 < 4 < 4.5 + 2(-x)^2 < 6+2x^2 regardless of the value for x x -4x – 3 y -2 -4(-2) – 3 = 8-3 5 -1 -4(-1) – 3 = 4-3 1 0 -4(0) – 3 = -3 -3 1 -4(1) – 3 = -4 – 3 -7 2 -4(2) – 3 = -8 – 3 -11