Download 1078 Sec1 Elementary..

Cartesian Coordinate System and Straight Line
1. Determine which, if any, of the ordered pairs listed satisfy the given equation.
1.1. 2y-4x = 10;
a. (7,1)
b. (1,7)
c. (5,0)
1.2. 3x + 2y = 12;
a. (2,3)
b. (0,6)
c. (3,0)
2. Find a general linear equation ( Ax + By = C) of the straight line that has the indicated
properties and sketch each line by defining x-intercept , y-intercept , or both.
a. Passes through origin and has slope -5.
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b. Has slope 0 and y-intercept  .
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c. Is horizontal and passes through (-3, -2).
d. Is vertical and passes through (-1,4).
e. Passes through (3,-1) and (-2, -9).
3. Find, if possible, the slope, x-intercept, and y-intercept of the straight line determined
by the equation, and sketch the graph.
3x-2y = 10
4. Find an equation of the line passes through (-3,2) and is parallel to 2x +3y = -6
5. Determine whether the lines are parallel, perpendicular, or neither. Also specify your
reason.
(a) y = 3, x =-1/3
(b) 3x + y = 4, x-3y+1=0
(c) x=3, x=-3
6. A house purchased for $198,000 is expected to double in value in 18 years. Find a
linear equation that describes the house’s value after x years.
7. Suppose consumers will demand 40 units of a product when the price is $12 per unit
and 25 units when the price is $18 each. Find the demand equation, assuming that it is
linear. Find the price per unit when 30 units are demanded.
8. Suppose a pizza company has a fixed cost of $500 and a total cost of $550 for total
production of 100 slices of pizza.
(a) Assume that the total cost equation is linear in quantity. Write a total cost
equation in relation to total pizza production. Let y be the total cost and x be the
total production.
(b) What is the slope of total cost equation? How would you interpret the slope of the
total cost equation?