1.) 1+10a-5a
Subtract 5a from 10a
Final Answer: 1+5a
3.) x-9-3x
Subtract 3x from x
Final Answer: -9-2x
5.) 1-4n+2n-1
Subtract 1 from 1
-4n+2n
Add
Final Answer: -2n
7.) 10k-3k
Subtract
Final Answer: 7k
9.) 5r+4-4
Subtract
Final Answer: 5r
140/300=14/30
14/30=7/15
So 7/15 is _
46.6%
Both of the other angles are 40° because a triangle has a total angle of 180° and an isosceles triangle means that at least two of the sides have to be the same length (two angles must be the same)
180 - 100= 80
80 ÷ 2 = 40