Question

Tính hợp lý: 

(-157) . (127 - 316) - 127 . (316 - 157)

Answer 1

(-157). (127 – 316) – 127. (316 – 157)

= (- 157). 127 + (-157). (-316) + (–127). 316 + (-127). (-157)

= -157. 127 + 157. 316 – 127. 316 + 127. 157

= [- (127. 157) + 127. 157] + (157. 316 – 127. 316)

= 0 + 316. (157 – 127)

= 316. 30

= 9 480.

Answer 2

\(\left(-157\right)\left(127-316\right)-127\left(316-157\right)=-157.127+157.316-127.316+157.127\)

\(=157.316-127.316=316\left(157-127\right)=316.30=9480\)