Question

Need help with number 7,8 and 9?

Answer 1

Q7: $y = 2x+3$

Q8: $y=-2x+5$

Q9: $m = -\frac{A}{B}$

Step-by-step explanation:

Q7: Given equation of line is:

$2x-y=1$

Converting into slope-intercept form

$2x-y-1 = 1-1\\2x-y-1+y = 0+y\\y = 2x-1$

Comparing with the standard slope-intercept form

$y = mx+b$

We get

m = 2

As the new line has same slope as given line

$m_1 = 2$

Given

b = 3

The equation is given by:

$y = m_1x+b$

Putting the values of slope and y-intercept

$y = 2x+3$

Q8: Given equation of line is:

$6x+3y = 12$

converting in slope-intercept form

$3y = -6x+12$

Dividing both sides by 3

$y = -2x+4$

The slope of line is: -2

The new line has same slope so,

m_1 = -2

Slope-intercept form of line is:

$y = m_1x+b$

Putting the value of slope

$y = -2x+b$

Putting the point (2,1) in the equation

$1 = -2(2) +b\\1 = -4 +b\\b = 4+1\\b = 5$

So the equation is:

$y=-2x+5$

Q9: Given equation is:

$Ax+By = C$

subtracting Ax from both sides

$Ax+By-Ax = C-Ax\\By = -Ax+C$

Dividing both sides by B

$\frac{By}{B} = \frac{-Ax+C}{B}\\y = -\frac{A}{B}x + \frac{C}{B}$

As the equation is in slope-intercept form, the co-efficient of x is the slope of line

So the slope is:

$m = -\frac{A}{B}$

Hence,

Q7: $y = 2x+3$

Q8: $y=-2x+5$

Q9: $m = -\frac{A}{B}$

Keywords: Equation of line, slope

Learn more about equation of line at:

• brainly.com/question/9621364
• brainly.com/question/9539036

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