Inequalities are just like regular equations with only one exception. Which is when yo multiply or divide by a negative number to both sides of the inequality sign you must flip it. But, for this inequality that rule will no apply. So, what I do to make it easier because I know we all see a different sign in an equation and we start to freak out. So, change the inequality sign to an equals sign to get a hang of working with them.
Example of changing an inequality sign to an equals sign:
Addition property of equality
or
Example of keeping the inequality sign
Addition property of equality
A.) it's a 90° angle
90=6x+4x+10
90=10x+10
-10 -10
80=10x
divide both sides by 10, x=8
B.) it's a 180° angle
180=5x+13+3x+7
180=8x+20
-20 -20
160=8x
divide both sides by 8, x=20
C.) it's a 180° angle
180=3x+5+2x+18+2x+17
180=7x+40
-40 -40
140=7x
divide both sides by 7, x=20
D.) it's a 180° angle
180=90+30+x
180=120+x
-120 -120
60=x
It would be the second choice or letter B - (0,12)
To get the y-intercept, set x as zero. Substitute then simplify. Negative six times negative two would equal to positive twelve.
Set: x = 0
Solution: f(x) = (0 - 6) (0 - 2)
f(x) = -6 x -2
Answer: y = 12
2(a+bc)=2a+2bc
3.(ab-cb-ba+bc)= 3ab-3cb-3ba+3bc
Since the brackets and multiplication have a higher order than the rest.
Cb=Bc
Ab=ba
Ac=Ca
Because multiplication is commutative.
2a+2bc + cb +ab + ac -(3ab-3cb-3ba+3bc)
2a + 2bc + cb + ab + ac(+ -3ab - - 3cb - -3ba +-3bc)
2a + 2bc + cb + ab + ac -3ab + 3cb + 3ba -3bc
2a + (2bc-3bc +cb + 3cb ) + (ab -3ab + 3ba) + ac
=2a + 3cb + ba+ ac OR 2a +3bc + ab + ac
The Or is just a different way to write it.
Hope this helps
