What is 6x+30=3x-42 whats the answer

Can some one me with this math problem?

Which shows one way to determine the factors of  x3  +  5x2  –  6x  –  30 by grouping? x(x2  –  5)  +  6(x2  –  5)x(x2  +  5)  –  6(x2  +  5)x2(x  –  5)  +  6(x  –  5)x2(x  +  5)  –  6(x  +  5)

What are potential hypotheses (explanations) regarding why there are ecological equivalents between many metatherians and eutherians? discuss your hypothesis in terms of the processes that could lead to the current ecologies and distributions of metatherians and eutherians.