Answer:
a) Intersection of the equations (1.4, 1.8)
b) Intersection of the equations (0, 2) and (1.2, -1.6)
Explanation:
Part a) y = 2x – 1 and x + 2y = 5
To find the intersection point, let's replace the first equation on the second one, so
x + 2y = 5
x + 2(2x - 1) = 5
Now, we can solve the equation for x
x + 2(2x) - 2(1) = 5
x + 4x - 2 = 5
5x - 2 = 5
5x - 2 + 2 = 5 + 2
5x = 7
5x/5 = 7/5
x = 1.4
Then, replace x = 7/5 on the first equation
y = 2x - 1
y = 2(1.4) - 1
y = 2.8 - 1
y = 1.8
Then, the graph of the lines is:
Where the intersection points with the axes for y = 2x - 1 are (0, -1) and (0.5, 0) and the intersection points with the axes of x + 2y = 5 are (0, 2.5) and (5, 0)
Part b) ^2 + ^2 = 4 and 3x + y = 2
First, let's solve 3x + y = 2 for y, so
3x + y - 3x = 2 - 3x
y = 2 - 3x
Then, replace y = 2 - 3x on the first equation and solve for x
x² + y² = 4
x² + (2 - 3x)² = 4
x² + 2² - 2(2)(3x) + (3x)² = 4
x² + 4 - 12x + 9x² = 4
10x² - 12x + 4 = 4
10x² - 12x + 4 - 4 = 0
10x² - 12x = 0
x(10x - 12) = 0
So, the solutions are
x = 0
or
10x - 12 = 0
10x = 12
x = 12/10
x = 1.2
Replacing the values of x, we get that y is equal to
For x = 0
y = 2 - 3x
y = 2 - 3(0)
y = 2 - 0
y = 2
For x = 1.2
y = 2 - 3(1.2)
y = 2 - 3.6
y = -1.6
Therefore, the intersection points are (0, 2) and (1.2, -1.6)
Then, the graph of the functions are:
Since ^2 + ^2 = 4 is a circle with radius 2, the intersection points with the axes are (2,0), (0, -2), (-2, 0) and (0, 2). Additionally, the intersections potins with the axis of the line 3x + y are (0, 2) and (0.667, 0)
