Help me please): yang no 8,9,dan 10

8. 180=x + 3x-5 + 2x-1
180=x+3x+2x-5-1
180=6x-6
180+6 =6x
186=6x
186/6=x
31=x

<C = <F
<B = <E
<A = <D

<D = 3x-5
=(3×31)-5
=93-5
=88

<F = 2x-1
=(2×31)-1
=62-1
=61

<E = x
=31.