a) 2×{120-2×[(2×X18)÷15+180]÷11}=200
120-2×[(2×X+18)÷15+180]÷11=100
-2×[(2×X+18)÷15+180]÷11=-20
(2×X+18)÷15+180=110
(2×X+18)÷15=110-180
(2×X+18)÷15=-70
2×X+18=-1050
2×X=-1068
x=-534
b) 2010⁰+{2×[3+(X-2²)× 5 ])÷6×7=2³
1+{2×[3+(X-2²)× 5 ])÷6×7=8
{2×[3+(X-2²)× 5 ])÷6=(8-1):7
{2×[3+(X-2²)× 5 ])÷6=1
2×[3+(X-2²)× 5 ]=6
3+(X-2²)× 5=3
(X-2²)× 5=0
X-2²=0
X=2²
X=4