7x+3(4x-8)=109
7x+12x-24=109
19x-24=109
19x=109+24
19x=133
X=133÷19
X=7
Y=(1/2 x)-2
My Work:
Say that the slop is "a" and that the y-intercept is "b".
For the slope:
First coordinate equation: -3=-2a+b
Second coordinate equation: -1=2a+b
Combine the equations. -3-(-1)=-2a-(2a)+b-(b)
Break down the parenthesis. -3+1=-2a-2a+b-b
Simplify the equation. -2=-4a
Divide both sides by -4 to get the answer to the slope. a=1/2
For the y-intercept:
Use the second coordinate's equation and the now known slope. -3=-2*1/2+b
Multiply -2 by 1/2 (Order of Operations). -3=-1+b
Add +1 to both sides to cancel the -1. -3+1=b
Finally, solve the solve -3+1 to get the answer to the y-intercept. b=-2
Taking the square root of both sides gives two possible cases,
or
Recall that
If 
and 
, we have
so in the equations above, we can write
Then in the first case,
(where 
is any integer)
and in the second,
Then the solutions that fall in the interval 
are
22-21.9 = 0.1
You round it off adding a zero .
The answer is 1.0
You multiply by 100
You get 100
