A+b+c= 180
<span>a = ?
</span><span>b = 2a - 10 (twice a minus 10)
</span><span>c = b + 25 (25 more than b)
</span><span>Substitute for b
c = (2a-10) + 25
</span><span>Now substitute back into a+b+c=180
a + (2a-10) + (2a-10+25) = 180
</span><span>Eliminate the parentheses
a + 2a - 10 + 2a - 10 + 25 = 180
</span><span>Combine like terms
5a + 5 = 180
</span><span>Subtract 5 from both sides
5a = 175
</span><span>Divide both sides by 5
a = 35
</span><span>Substitute into the equation for b.
b = 2a -10 = 2*35 - 10 = 70 - 10 = 60
</span><span>Add 25 to b to get c.
c = 60 + 25 = 85</span><span>Check by adding them up.
35 + 60 + 85 = 180
Done.</span>
B.
The cost for x children and y adults to go to the movies if adult tickets are $11 and child tickets are $6.
Example 3 children and 2 adults ( 6(3) + 11(2) )
8 > 7 + 
Subtract 7 from both sides
1 > Multiply both sides by 6
6 > x Flip it around so it's easier to read
x < 6
You can graph your answer by drawing an open circle at the 6 and coloring the line to the left. The circle should be open, because x is <em>less than 6</em>, not less than or equal to. You would color to the left to show that x can be anything less than 6.
