0 = 66 – 6d. Solve for d to get –66 = –6d, so 11 = d. Plug 11 in for d and set the quadraticto 0 to get 0 = 2x^2 – 11x − 6. Factor the equation to get 0 = (x − 6)(2x + 1). The other zeroof the equation is when 2x + 1 = 0. Solve for x to get 2x = –1, or x = . The correctanswer is (C).
D The flu shot is most effective against Strain C, which is least prevalent in March. To
determine the overall efficacy of the flu shot at this time, multiply the prevalence of each
strain of flu by the efficacy of the flu shot against that strain, and then add those products to
get a weighted average of the efficacy of the shot: (0.23 × 0.35) + (0.25 × 0.13) + (0.13 ×
0.76) +(0.39 × 0.68) = 0.477 = 47.7%, which is closest to (D).
3 Solve the equation for v. Take 9 > 3v – 3 and add 3 to both sides to get 12 > 3v. Now
divide both sides by 3 to find that 4 > v. Therefore, the largest integer that v could be is 3.
Grid in 3.
or 0.83
Start by multiplying the second fraction in the denominator of the equation by to get = 1. Combine the fractions in the denominator to get = 1. Reduce the fractionin the denominator to get = 1. Dividing by a number is the same as multiplying by itsreciprocal, so the equation becomes × y = 1. Multiply both sides of the equation by toget y = . The correct answer is .- 1,279 614 students voting for Candidate A represents 0.48 of the population out of 1. Set up a
proportion: , where x is the total number of students in the school. Cross-multiply: 0.48x = 614. Divide both sides by 0.48 and you get approximately 1,279.
or 0.384 or 0.385
Draw a right triangle and label a non-right angle θ. SOHCAHTOA tells you that tangent is