Answer:
x = -2bm/(m²+1)
Step-by-step explanation:
One line has equation
... y = mx + b
The slope of the perpendicular line is the negative reciprocal of the slope of the original line. The perpendicular line with the opposite y-intercept has equation
... y = (-1/m)x - b
The point of intersection is where the x- and y-values are equal, so ...
... mx + b = (-1/m)x - b
... (m +1/m)x = -2b . . . . . . . add 1/m - b to both sides
... (m²+1)x = -2bm . . . . . . . multiply by m
... x = -2bm/(m²+1) . . . . . . divide by the coefficient of x
Answer:
7x-5
Step-by-step explanation:
Answer:
2 solutions
Step-by-step explanation:
I like to use a graphing calculator to find solutions for equations like these. The two solutions are ...
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To solve this algebraically, it is convenient to subtract 2x-7 from both sides of the equation:
3x(x -4) +5 -x -(2x -7) = 0
3x^2 -12x +5 -x -2x +7 = 0 . . . . . eliminate parentheses
3x^2 -15x +12 = 0 . . . . . . . . . . . . collect terms
3(x -1)(x -4) = 0 . . . . . . . . . . . . . . . factor
The values of x that make these factors zero are x=1 and x=4. These are the solutions to the equation. There are two solutions.
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<em>Alternate method</em>
Once you get to the quadratic form, you can find the number of solutions without actually finding the solutions. The discriminant is ...
d = b^2 -4ac . . . . where a, b, c are the coefficients in the form ax^2+bx+c
d = (-15)^2 -4(3)(12) = 225 -144 = 81
This positive value means the equation has 2 real solutions.