1 more Linear Math Problem. (Find slope and y-intercept)

1. Sep 16, 2010

nukeman

1. The problem statement, all variables and given/known data

Find the slope m and y-intercept (0,b) of the line
2x + 4y =8

2. Relevant equations

I am still having troubles with finding the slope and y-intercept of a line.

Can you please solve this equation for me, but show me the steps, and break it down? It would really help. Include why you did that certain step.

3. The attempt at a solution

You guys are great. I really appreciate the great help!

2. Sep 16, 2010

rock.freak667

2x + 4y =8

the key is to make the coefficient of 'y' equal to 1.

So what number should you divide by to make the coefficient of 'y' equal to 1?

3. Sep 16, 2010

nukeman

Is it 4 ?

4. Sep 16, 2010

rock.freak667

Right so divide by '4' and move the term in 'x' to the other side of the equation. What do you get?

5. Sep 16, 2010

nukeman

can u clearify this for me?

6. Sep 17, 2010

eumyang

Personally, I would move the term with the x on the other side before dividing both sides by 4.

To the OP: you really need to be familiar with the properties of equality. For instance, in the subtraction property of equality you can subtract something from both sides:
\begin{aligned} a + b &= c \\ a + b - b &= c - b \\ a &= c - b \end{aligned}

With the division property of equality, you can divide from both sides, as long as you're not dividing by zero:
\begin{aligned} ab &= c \\ \frac{ab}{b} &= \frac{c}{b} \\ a &= \frac{c}{b} \\ \end{aligned}
(b ≠ 0)

Now use these properties to solve for y in your equation.

69

7. Sep 17, 2010

Duncannn

First make your line into a known function of the form
l:y=ax + b

Finding the y-intersect set x to zero (b), finding the x-intersect set y to zero.
The slope is the rate at which your line changes vertically which is given by 'a'