When do you use a solid line for graphing a linear inequality?
1 answer:
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Answer:
Step-by-step explanation:
a)7x + 2 = -19 {subtract 2 from both sides}
7x + 2 - 2 = -19 - 2
7x = -21 {Divide both sides by 7}
7x/7 = -21/7
x = -3
b) 3x - 1/3 = 5
3x - 1/3 +1/3 = 5 + 1/3 {Add 1/3 to both sides}
3x =15/3 + 1/3
3x =16/3
3x/3 = 16/3*3 {Divide both sides by 3}
x =16/9
x =1 7/9
c) 5x - 4 = 21
5x -4 + 4 = 21 +4 {Add 4 to both sides}
5x = 25
5x/5 = 25/5 {Divide both sides by 5}
x = 5
d) -7x = 21 {Divide both sides by -7}
-7x/-7 = 21/-7
x = -3
e) 18 - 7x = -3
18 - 7x - 18 = -3 - 18 {Subtract 18 from both sides}
-7x = -21 {Divide both sides by -7}
-7x/-7 = -21/-7
x = 3
f) 3(x+4) = 21 {use distributive property}
3x + 3*4 = 21
3x + 12 = 21
3x + 12 - 12 = 21 - 12 {Subtract 12 from both sides}
3x = 9 {Divide both sides by 3}
3x/3 = 9/3
x = 3
g) 3x - 9 = 5x - 3 {add 9 to both sides}
3x - 9 + 9 = 5x - 3 + 9
3x = 5x + 6
3x - 5x = 5x + 6 - 5x { subtract 5x form both sides}
-2x = 6 {Divide both sides by -2}
-2x/-2 = 6/-2
x = -3
h) 4x + 6 - 7x + 9 = 18 {Add the like terms}
-3x + 15 = 18 {Subtract 15 from both sides}
-3x + 15 -15 = 18 - 15
-3x = 3 {Divide both sides by -3}
-3x/-3 = 3/-3
x = -1
Multiply both sides by 9
-4x = -324 {Divide both sides by -4}
-4x/-4 = -324/-4
x = -81
{Add 6 to both sides}
{Multiply both sides by 8}
{Divide both sides by -7}
x =-2*8
x = -16