Two Step Equations
Solve : y - 19 = 27
y-19= 27
+19 +19
y = 46
Solve: -20 = 4x+ 6x
-20 = 4x+ 6x
-20= 10x
x = -2
Which inequality is graphed on the number line:
closed circle at -6 and shaded to the right
x is greater than or equal to -6
The sum of 6 times a number and fifteen is 42
6x + 15 = 42
What is a coefficient?
Number in front of the variable
Solve: x + 12 = 36
x+12=36
-12 -12
x = 24
Solve: 28 = -1k + 16 - 2k - 9
28 = -1k + 16 - 2k - 9
28= -3k + 7
-7 -7
21= -3k
x = -7
Solve: 3x > -21
3x > -21
3. 3
x > -7
Translate: The difference of a number and 6 is 19
n - 6 = 19
If you divide or multiply by a negative, what must you do?
FLIP the inequality sign
Solve 7x - 5 = 58
7x - 5 = 58
+5. +5
7x. =63
7 7
x= 9
Solve: 4( 2n - 7 ) = 20
4( 2n - 7 ) = 20
8n - 28 = 20
+28. +28
8n = 48
n= 6
Solve: 3x + 15 ≤ 21
3x + 15 ≤ 21
-15. -15
3x ≤ 6
x ≤ 2
4 + x < -6
3
1/ 4 x - 15 = 80
What would be your first step ?
Adding 15 to both sides
Solve : 9x - 5 = 76
9x - 5 = 76
+5. +5
9x. =81
9 9
x= 9
Solve: -60 = -5 ( w + 2 )
-60 = -5 ( w + 2 )
-60 = -5w - 10
+10. +10
-50 = -5w
10 = w
Solve: -5x + 2 < 37
-5x + 2 < 37
-2. -2
-5x < 35
x < -7
Write an inequality
Megan wants to spend less than $300 planning a party. She spent $75 on food and wants to buy decorations that are $10each. How many decorations can she buy?
10x + 75 < 300
The word inverse means
opposite
Solve: 2x + 7 + 3x = -18
2x + 7 + 3x = -18
5x + 7 = -18-7 -7
5x = -25
x = -5
Solve: 6 ( v - 5 ) - 2v = 2
6 ( v - 5 ) - 2v = 2
6v - 30 - 2v = 2
4v - 30 = 2
+30. +30
4v = 32
v = 8
Solve: 2(x - 3) ≤ -10
2(x - 3) ≤ -10
2x - 6 ≤ -10
+6. +6
2x ≤ 4
x ≤ 2
7n - 25 < - 39
Write the inequality using math terms/vocabulary:
x - 5 ≤ 21
5 less than a number is less than or equal to 21