body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

Big Ideas Math: Modeling Real Life, Grade 8

BI

Big Ideas Math: Modeling Real Life, Grade 8 View details

Practice Test

Continue to next subchapter

Exercise 5 Page 192

What information can you learn from the slope-intercept form of an equation?

Equations written in slope-intercept form follow a specific format. y= mx+ b In this form, m represents the slope of the line and b represents the y-intercept.

Identifying the Slope and y-intercept

Since the given equation is not in slope-intercept form, let's rewrite it so that it will be easier to identify the slope and y-intercept.

- 3x+6y=12

LHS+3x=RHS+3x

- 3x+6y+3x=12+3x

▼

Add terms

CommutativePropAdd

Commutative Property of Addition

6y- 3x+3x=3x+12

Add terms

6y=3x+12

.LHS /6.=.RHS /6.

6y/6=3x+12/6

▼

Simplify left-hand side

MovePartNumRight

a* b/c=a/c* b

6/6y=3x+12/6

Calculate quotient

1y=3x+12/6

Identity Property of Multiplication

y=3x+12/6

▼

Simplify right-hand side

Write as a sum of fractions

y=3x/6+12/6

MovePartNumRight

a* b/c=a/c* b

y=3/6x+12/6

a/b=.a /3./.b /3.

y=1/2x+12/6

Calculate quotient

y=1/2x+2

Below we have highlighted the slope m and y-intercept b. y= 12x+ 2 The slope is 12. The y-intercept is 2, so the graph crosses the y-axis at the point (0, 2).

Graphing the Equation

A slope of 12 means that for every 2 units we move in the positive horizontal direction, we move 1 unit in the positive vertical direction. m= 1/2 ⇔ rise/run=1/2 To graph the equation, plot the y-intercept and then use the slope to find another point on the line.

Subchapter links

Exercises