Die korrekte Antwort lautet:
-1 ⋅ ( - 5 ) = 5

$50·(47-\left(19+37\right))$

= $50·\left(47-19-37\right)$

= $50·\left(-9\right)$

= $-450$

$-2\cdot {\left(-1\right)}^3-{\left(-3\right)}^2$

= $-2\cdot \left(-1\right)-9$

= $2-9$

= $-7$