Toán Bỏ ngoặc rồi tính 1) 10 – [12 – (-9 – 1)] 2) (38 – 29 + 43) – (43 + 38) 3) 271 – [(-43) + 271 – (-17)] 4) -144 – [29 – (+144) – (+144)] 19/07/2021 By Liliana Bỏ ngoặc rồi tính 1) 10 – [12 – (-9 – 1)] 2) (38 – 29 + 43) – (43 + 38) 3) 271 – [(-43) + 271 – (-17)] 4) -144 – [29 – (+144) – (+144)]
`1)10-[12-(-9-1)]` `=10-(12+9 + 1)` `=10-(10+12)` `=10 – 10 – 12` `=-12` `2)(38-29+43)-(43+38)` `= 38 + (-29) + 43 + (-43) + (-38)` `= [38 + (-38)] + [43 + (-43)] + (-29)` `= -29` `3) 271 – [(-43) + 271 – (-17)]` `=271+43-271-17` `=(271-271)+(43-17)` `=26` `4)-144 – [29 – (+144) – (+144)]` `=-144-29+144+144` `=(-144+144+144)-29` `=115` Trả lời
Đáp án: 1) -12 2) -29 3) 26 4) 115 Giải thích các bước giải: 1) 10 – [12 – (-9 – 1)] = 10 – (12 + 9 + 1) = 10 – (10 + 12) =10 – 10 – 12 = (10 – 10) – 12 = 0 – 12 = -12 2) (38 – 29 + 43) – (43 + 38) = 38 + (-29) + 43 + (-43) + (-38) = [38 + (-38)] + [43 + (-43)] + (-29) = 0 + 0 + (-29) = -29 3) 271 – [(-43) + 271 – (-17)] = 271 – (-43 + 271 + 17) = 217 + 43 – 271 -17 = (217 – 217) + (43 – 17) = 0 + 26 = 26 4) -144 – [29 – (+144) – (+144)] = -144 – (29 – 144 – 144) = -144 – 29 +144 + 144 = (-144 + 144) – 29 + 144 = 0 – 29 +144 = -29 +144 = 115 Trả lời