What is the slope-intercept form of the equation y+18= 2(x-1)

Question

A. y= -2x-20

B. y= -2x-16

C. y= 2x-6

D. y= 2x-20

Answer 1

Hi,

Just for a starter, this is a liner equaion, that is a first order equation, which can have three forms. 

The first form:

Slope - y intercept form that looks like this:

Y=mX+b

where m is the slope and b is the Y-intercept, that is where the line intersect with the Y-axis.

The second form:

Slope- point form:

Y-y1=m(X-x1)

Again, m the slope and (x1,y1) is any point that satisfies the line, i.e. lies on the line.

The third form:

Standard form:

aX+bY=c

Where a, b, and c are numbers, loosly speaking.

Getting back to your question, then the question basically asking to switch from the second form back to the first form, which is way widly used and the answer is option D using the following:

Y+18=2X-2 by distributing multiplication over subtraction(or distributing multiplicatin over addition if you thought the operation is addition and the sign for the number was negative)

Y=2X-20 by subtraction 18 from both sides (again you could think of it as  adding -18 instead)

I just wanted to mention this because it is heavily used in standarized tests like ACT, SAT, Common Core and the forms are used interchangeably in most Algebra books I have taught from so far.

Answer 2

When finding the slope intercept form, we are manipulating the equation to solve for y.

 

 

First, distribute on the right side.

 

y + 18 = 2x - 2

 

 

Subtract 18 on both sides of the equation.

 

y = 2x - 20

Answer 3

The answer is D 

 

y =2x-2-18

 

= 2x-20