jumpstart your brain! 5 questions – 5 points you have 1 minute per question. good luck
TRANSCRIPT
Jumpstart your brain!
5 Questions – 5 points You have 1 minute per question.Good luck.
REMEMBER
READYSET
GO!
Show the work!
1)The slope of the line through (5,-4) and
(5,-10) is …
a) positive
b) negative
c) zero
d) undefined
Show the work!
2)The slope of the line passing through (a,b) and (c,d) is …
a) b)
c) d)
d cb a--
d ba c--
a cb d--
b da c--
Show the work!
3) Which equation best describes the graph?
a) y=2xb) y=-2xc)
d)
1y x
2=
1y x
2=-
Show the work!
4) Which equation does NOT model a direct variation?
a) y=4x b) y=22x
c) y=3x+1 d)1
y x2
=
Show the work!
5) Evaluate -2x-7y if x=-5 and y=-4…
a) 38 b) 43
c) 227 d) 243
TIMES UP…
Get ready to check your answers
READYSET
GO!
Answers: Check it. Circle the number you got right.
1) D2) B3) D4) C5) A
Chapter 5.3-5.4
Analyzing Linear Equations
5.3 Slope-Intercept Form
The slope-intercept form looks like this…
y mx b= +
slope=rise over run
Y-interceptwhere the line crosses the y-axis
Write a slope-intercept equation
Step 1) Find mStep 2) Find bStep 3) Plug the values for m and b
into y=mx+b
***When you are done, the only variables left will be x and y
Example: Write a SI equation
Write an equation (in slope-intercept form) for the line with slope 3 and y-intercept -2
y=mx+b Slope-intercept form
Substitute m and b
Simplify
y=3x+-2
y=3x-2
Step 1) Find m
Step 2) Find b
Step 3) Plug in m and b
Write a slope-intercept equation
Write an equation (in slope-intercept form) for the line shown.
2 1
2 1
y ym
x x
-=
-
2 1
2 1
y ym
x x
-=
- Slope formula
Substitute (0,3) and (2,-1)
1 3m
2 0- -
=-
Simplify
Step 1) find m
4m 2
2-
= =-
Write a slope-intercept equation
Write an equation (in slope-intercept form) for the line shown.
2 1
2 1
y ym
x x
-=
-Step 2) find b
Slope-Intercept form
b=3
Substitute m, b
y=mx+b
y=-2x+3
Step 3) plug in m & b
Graph a Slope-Intercept Equation
Step 1) Plot bStep 2) From b, rise and runStep 3) Connect
Graph a Slope-Intercept equation…
Graph
2y x 1
3=- +Step 1) Plot b
Step 2) From b, rise and run
2 2m or
3 3- +
=+ -
2y x 1
3=- +
Step 3) Connect
Graph an equation in standard form…
Graph
5x 3y 6- =
BEFORE YOU CAN BEGIN>>>Put in SI form This means SOLVE FOR Y
5x 3y 6- =
5y x 2
3= -
3y 5x 63 3
- - +=
- -
3y 5x 6- =- +Original equation
Subtract 5x
Divide by -3
Simplify
Graph an equation in standard form…
5y x 2
3= -
Step 1) Plot b
Step 2) From b, rise and run
Ok, now we have
5 5m
3 3+ -
= =+ -
Step 3) Connect
Example: Write a SI equation
Write an equation (in slope-intercept form) for the line through (1,5) with slope 2
y=mx+b Slope-intercept form
Substitute 1, 5, and 2
Simplify
5=2(1)+b
5=2+b
Step 1) Find m
Step 2) Find b
5-2=b
3=b
Subtract 2
Simplify
Example: Write a SI equation
Write an equation (in slope-intercept form) for the line through (1,5) with slope 2
y=mx+b Slope-intercept form
Substitute m and by=2x+3
Now we know m=2 and b=3…
Step 3) Plug in m and b
Example: Write a SI equation
2 1
2 1
y ym
x x
-=
-
4 1m
6 3- - -
=- -
Write an equation (in slope-intercept form) for the line through (-3,-1) and (6,-4)
Slope formula
Substitute
Step 1) Find m
Simplify3 1
m9 3-
= =-
Example: Write a SI equation
13
-
1 1 b- = +
Write an equation (in slope-intercept form) for the line through (-3,-1) and (6,-4)
Slope Intercept Formula
Substitute a point and m
Simplify
Step 2) Find b
y=mx+b
OK…now we know m=
11 ( 3) b
3- =- - +
1 1 b- - =2 b- =
SubtractSimplify
Example: Write a SI equation
13
-
1y x 2
3=- +-
Write an equation (in slope-intercept form) for the line through (-3,-1) and (6,-4)
Slope Intercept Formula
Substitute m and b
Simplify
Step 3) Plug in m and b
y=mx+b
OK…now we know m= and b=-2
1y x 2
3=- -
Homework
P275-276: 17, 31-37oddP284: 11, 13, 19-23oddALL ANSWERS ARE IN THE BOOK.
YOU MUST SHOW THAT YOU CAN GET THE ANSWER ALGEBRAICALLY.
If you get stuck try www.hotmath.comUsername BHSHAWKS06