Bài 111 trang 99 SGK Toán 6 tập 1

Tính các tổng sau:

a) \( [(-13) + (-15)] + (-8) \)

b) \(  500 – (-200) – 210 - 100\)

c) \( –(-129) + (-119) - 301 + 12\)

d) \( 777 – (-111) –(-222) + 20\)

Lời giải

a) \((–13 ) + (–15) + (–8)\)

\(= – (13 + 5 + 8)\)

\(= –36.\)

b) \(500 – (–200 ) – 210 – 100\)

\(= 500 + 200 – 210 – 100\)

\(= 500 + 200 – (210 + 100)\)

\(= 700 – 310 = 390.\)

c) \(–(–129) + (–119) – 301 + 12\)

\(= 129 – 119 – 301 + 12\)

\(= (129 + 12) – (119 + 301)\)

\(= 141 – 420\) 

\(= –279.\)

d) \(777 – (–111) – (–222) + 20\)

\(= 777 + 111 + 222 + 20\)

\(= (777 + 111 + 222) + 20\)

\(= 1110 + 20 = 1130. \)


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