Question

work out the equation of the line which has a gradient of -2 and passes through the point (1,7)

Answer 1

Given :

• Slope or gradient of line = -2

• point through which the line passes through = (1,7)

To find :

• equation of the line

Concept used :

• Equation of line whose slope is m and it passes through ( h,k) :-

$(y - k) = (x - h)m$

Solution :

Equation of line whose slope is (-2) and it passes through ( 1,7) :-

⟹ $(y - 7) = (x - 1)( - 2)$

⟹ $y - 7= - 2x + 2$

⟹ $y = - 2x + 2 + 7$

⟹ $y = - 2x + 9$

⟹ $y + 2x = 9$

or

⟹ $2x + y = 9$

Answer :

$2x + y = 9$

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Verification of answer :-

We can verify our answer by putting (1,7) in the equation- 2x+y=9

⟹ LHS = (2×1)+7

⟹ LHS = 2+7

⟹ LHS = 9

Therefore , LHS = RHS.

Also , you can find out gradient or slope from the equation and verify your answer.

⟹ Slope = - (coefficient of x) / (coefficient of y)

⟹ Slope = - 2 /1

⟹ slope = -2

hence verified

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Answer 2

i dont know the whole thing but these will help you get some marks

Y=-2x+7

7=-2x+c

7=-2+c

7=-2+9