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Solution

For context free languages, equivalence problem is undecidable.

So,

$L(G_1)=L(G_2)$ is undecidable.

Also, inclusion problem for context free languages is undecidable.

So,

$L(G_2)\subseteq L(G_1)$ is undecidable.

Now,

$L(G_1)=R$

is also undecidable because if $R=\Sigma^*$, then this becomes CFL universality problem:

$L(G_1)=\Sigma^*$

which is undecidable.

Therefore, all three problems are undecidable.