Chapter 10 - Section 10.3 - Geoetric Sequences and Series - Exercise Set - Page 1073: 5

$10,-40, 160,-640,2560$

Here $ a_{n}=-4a_{n-1}$ We are given that $ a_1=10$ $ a_2=-4a_{2-1} = (-4)(10)=-40 ;\\ a_3=-4a_{3-1} = (-4)(-40)=160 ; \\ a_4= -4a_{4-1} = (-4)(160)=-640; \\ a_5=-4a_{5-1} = (-4)(-640)=2560$ Hence, the first five terms are: $10,-40, 160,-640,2560$