Question

multiply: (-10)(-9)(-1)(+2)(-5)

Explanation:

Step1: Multiply first two numbers

$(-10)\times(-9)=90$

Step2: Multiply result by third number

$90\times(-1)= - 90$

Step3: Multiply new result by fourth number

$-90\times(+2)=-180$

Step4: Multiply latest result by fifth number

$-180\times(-5)=900$

Answer:

$900$