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>
36 is the answer, hope this helps.
I believe 15 and 13. 13-15=-2 and added is 28....?
3x = 5(x-4)
I am not sure about the equal sign though.
