Math 2

Learn Math Part 2

100

review: 2x-5=3

1. get rid of 5 by adding 5 -5+5=0 and add 5 to 3 3+5=8 2x=8

2. divide 8 by 2 8/2=4

x=4

200

example 1: 37/100

1. divide 37 by 100 37/100=0.37

answer = 0.37

Example 2: 37%

1. divide 37 by 100 37/100=0.37

answer=0.37

25/100

25%

0.25

300

example: 9n-6=5n+18

1. get rid of 5n by subtract 5 5-5=0 also take away 5 from 9n 9-5=4 4n-6=18

2. get rid of -6 by adding 6 -6+6=0 also add 6 to 18 18+6=24 4n=24

3. divide 24 by 4 as shown 24/4=6

n=6

4x+3=-5x+21

1. get rid of -5x by adding 5 -5+5=0 also add 5 to 4x 5+4=9 9x+3=21

2. get rid of 3 by subtract 3 3-3=0 also subtract 3 from 21 21-3=18 9x=18

3. divide 18 by 9 18/9=2

x=2

400

example: m=2 b=? y=2x+b (3, 5)

1. use this equation to find b (y-y₁)=m(x-x₁)

2. substitute (y-5)=2(x-3)

3. Combine 2(x-3) 2 x X =2x 2x-3=-6 (y-5)=2x-6

4. get rid of -5 by adding 5 -5+5=0 also add 5 to -6

-6+5=-1 y=2x-1

answer=y=2x-1

m=3 b=? (5, 3) y=3x+b

1. make equation (y-y₁)=m(x-x₁)

2. substitute (y-3)=3(x-5)

3. combine 3(x-5) 3 x X=3x 3x-5=-15 (y-3)=3x-15

4. get rid of -3 by adding 3 -3+3=0 also add 3 to -15 -15+3=-12 y=3x-12

answer=y=3x-12

500

Review: m=50 b=1050 put it in slope form

y=50x+1050

three-step equations

100

3x+4=2x-7

x=-11

200

5x+2=10x-5

x=7/5

300

10-2x=4(5+10)-6

x=-22

400

9n-6=5n+18

n=6

500

7x+3=2x+13

x=2

decimal

100

55/100

55%

0.55

200

37/50

74%

0.74

300

65/100

0.65

400

27%

0.27

500

150/100

150%

1.50 or 1.5

medium slope

100

m=2 b=(0+5) put it in slope form

y=2x+5

200

m=5 b=(37+25) put it in slope form

y=5x+62

300

m=(9+5) b=(88-45) put it in slope form

y=14x+43

400

m=2 b=? (2,3) put it in slope form

y=2x-1

b=-1

500

How to find b

(y-y₁)=m(x-x₁)

multi-step equations

100

3(x+1)=5+x

x=1

200

7x-9=5

x=2

300

-5x+4+2x= if x=-4

16

400

3x-5=-26

x=-7

500

-4(-3n-8)=10n+20

n=-6