Answer:
y = -1
Step-by-step explanation:
The standard form of equation of a line is y = mx+b
m is the slope
b is the y intercept
Get the coordinate of the point of interception of the line 2x - y = 9 and 3x - 7y = 19
Make y the subject of the formula in both expressions
For 2x - y = 9
- y = 9- 2x
y = 2x - 9
Similarly for 3x - 7y = 19
-7y = 19 - 3x
7y = 3x - 19
y = 3/7 x - 19/7
Equating both expressions
2x - 9 = 3/7 x - 19/7
Multiply through ny 7
14x - 63 = 3x - 19
14x - 3x = -19 + 63
11x = 44
x = 44/11
x = 4
Since y =2x - 9
y = 2(4) - 9
y = 8-9
y = -1
Hence the coordinate of intersection is at (4, -1)
Get the equation of the line passing through (-3, -1) and (4, -1)
Slope m = -1+1/4+3
m = 0/7
m = 0
Get the intercept
Substitute m = 0 and (-3, -1) into y = mx+b
-1 = 0(-3) + b
-1 = b
b = -1
Get the required equation
Recall that y = mx + b
y = 0x + (-1)
y = -1
Hence the required equation is y = -1
Answer:
<h2>D</h2>
Step-by-step explanation:
If pair of ratios does form a true proportion then:
Answer:
Step-by-step explanation:
The first step is to find the slope. Use the slope formula
m = (y2-y1)/(x2-x1)
The two points are (x1,y1) = (-1,5) and (x2,y2) = (2,-1)
So,
x1 = -1
y1 = 5
and
x2 = 2
y2 = -1
will be plugged into the slope formula to get...
m = (y2-y1)/(x2-x1)
m = (-1-5)/(2-(-1))
m = (-1-5)/(2+1)
m = (-6)/(3)
m = -2
The slope is -2
Use m = -2 and one of the points to find the y intercept b. I'll use the point (x,y) = (-1,5) ---> x = -1, y = 5
y = mx+b ... slope intercept form
5 = -2*(-1)+b
5 = 2+b
5-2 = 2+b-2
3 = b
b = 3
The y intercept is 3
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m = -2 is the slope
b = 3 is the y intercept
Therefore y = mx+b turns into y = -2x+3 as the equation that goes through the two points
