Dividing by a half is the same as multiplying by two. 3/4 multiplied by 2 is

or, in improper fraction form

or, in decimal form, 1.5

We need to solve for x, we need to get x alone

Lets start by removing -5
Add 5 on both sides


Now to isolate x , we need to remove the square from x
To remove square , take square root on both sides

square and square root will get cancelled

So
and 
Step-by-step answer:
A line with slope (or gradient) m, passing through a point (x0,y0) can be represented by the equation:
(y-y0) = m(x-x0) ......................(1)
Here,
(x0,y0) = (1,7), and
slope/gradient = -2
Substitute values into (1) above gives
(y-7)=2(x-1)
Expand and simplify
y-7 = 2x-2
y =2x -2 + 7
y=2x+5
is the final answer.
It does match-
The Y-Intercept is 12
And the slope is -3/1
You can confirm this by counting rise over run in the graph
Starting at the Y-Intercept (Y=12) the graph goes down 3 units (-3) over 1 unit (1)
This confirms that the slope is -3/1
3x + 8 = 3x - 5
3x - 3x + 8 = -5
8 = -5 (incorrect)
this means there is no solution, because whatever number u sub in for x, it will not come out true