Find the gradient of the line 2y = 8x + 1 Find the y-intercept of the line 4y + 8x = -8

Bonus = Does the point (1 ,12) lie on the line y = 3x + 8 ? =

Does the point (-2 ,10) lie on the line y = 14 + 2x

gradient=4      y intersept: B(0;-2)   Point (1;12) doesn't lie on y=3x+8

(-2,10) lies on the line  y=14+2x

Step-by-step explanation:

2y=8x+1 => divide both sides by 2=> y=4x+1/2  => gradient = 4

4y+8x= -8 => 4y= -8-8x => y=-2-2x   . -2 - I indicated this number with the bold ( this ratio is the y coordinate of y- intersept. x coordinate=0

So the y-intersept is (0;-2)

We have a point (1;12)   1 is x coordinate of the point and 12 is y coordinate.

Put 1 and 12 instead x and y in the given formula. If we get the correct expression => the point lies on the line, if the expression is false=> doesn't lie on the line.

Now lets check !

12=3*1+8

12=  11  - false => the point  (1;12) doesn't lie on y=3x+8

Similarly proceed:  10=14+2*(2)

10=14-4

10=10 - right ! Point (-2;10)  lies on y=14+2x

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18