Đề thi Olympic Tiếng Anh lớp 9 vòng 23 năm 2013 - 2014

2x + 3y = 12 and 2x - y = 4, what is the value of x + y?

The height, h(t), in feet of an object thrown into the air with an initial upward velocity of 63 feet per second is given by the formula h(t) = -16t2 + 63t, where t is the time in seconds. What is the height of the object after 3 seconds?

A taxi ride cost $29.40. The driver charged $3 plus $0.40 per 0.2 mile traveled. How far did the taxi travel on this trip?

The average price of a movie ticket in the year 2000 was $5.39. The average price of a movie ticket in the year 2004 was $6.21. Assuming the increase is linear, what would be the approximate price of a movie ticket in the year 2009?

2x + 6y = 9
y = -x/2 + 2

What is the value of y in the system of equations above?

A car's speed before a sudden stop can be estimated by the formula S = √30gk where S = speed of the car in mph, g = drag factor, and k = length of skid mark in feet. The drag factor during a recent crash was 0.8. What was the approximate speed of the car if it created skid marks 193 feet long?

Multiply: (3x - 4)(6x + 7)

The formula P = 96.3F/SL can be used to calculate the precipitation rate at which sprinklers spread water. In the formula, P is the precipitation rate, F is the rate of water flow, S is the amount of space between each sprinkler, and L is the space between two rows of sprinklers. If the space between each sprinkler is 6, and the space between rows is 7, what is the approximate rate of water flow that will result in a precipitation rate of 20?

At the airport, the new runway will be parallel to a nearby highway. On the scale drawing of the airport, the equation that represents the highway is 6y = 8x - 11. Which equation could represent the new runway?

The midpoint of XY is point M(-12, 5). If the coordinates of X are (3, -3), what are the coordinates of Y?