254x399-145/254+399x253 các bạn tính nhanh cho mình nha
tính nhanh
254x399-145
___________
254+399x253
A = \(\dfrac{254\times399-145}{254+399\times253}\)
A = \(\dfrac{\left(253+1\right)\times399-145}{254+399\times253}\)
A = \(\dfrac{253\times399+399-145}{254+399\times253}\)
A = \(\dfrac{253\times399+254}{254+399\times253}\)
A = 1
a) \(254x399-145=\left(250+4\right)\left(400-1\right)-145\)
\(=100000+1600-250-145-4=101600-\left(250+145+4\right)\)
\(=101600-399=101201\)
b) \(254+399x253=254+\left(400-1\right)x\left(250+3\right)\)
\(=254+100000+1200-250-3\)
\(=101454-250-3=101201\)
b2 tính nhanh
254x399-145 / 254+399x253
\(\frac{254.399-145}{254+399.253}\)
\(=\frac{253.399+399-145}{254+399.253}\)
\(=\frac{253.399+254}{254+399.253}=1\)
Trả lời
254.399-145/254+399.253
=253.399+399-145/254+399.253
=253.399+254/254+399.253
=1.
Tính nhanh:
\(\frac{254x399-145}{254+399x253}\)
Tính nhanh:
\(\frac{254x399-145}{254+399x253}\)
254 × 399 - 145 / 254 + 399 × 253
= (253 + 1) × 399 - 145 / 254 + 399 × 253
= 253 × 399 + (399 - 145) / 254 + 399 × 253
= 253 × 399 + 254 / 254 + 399 × 253
= 1
\(\frac{254x399-145}{254+399x253}\)
\(=\frac{253x399+399-145}{254+399x253}\)
\(=\frac{253x399+254}{254+399x253}=1\)
\(\frac{254.399-145}{254+399.253}=\frac{254.399-145}{\left(254-1\right).399+254}\)\(=\frac{254.399-145}{254.399-399+254}=\frac{254.399-145}{254.399-145}=1\)
DẤU . LÀ DẤU NHÂN NHA
254x399-145/254+399x253
254 x 399 - 145/254 + 339 x 253
= 101346 - 145/254 + 85767
= 187112,4291
254x399-145/254+399x253
\(\frac{254\cdot399-145}{254+399\cdot253}=\frac{\left(253+1\right)\cdot399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+254}{254+399\cdot253}\)
\(=1\)
Bài 1 : a. Tính nhanh, tính hợp lí :
254x399-145/254+399x253
b.Tìm x :
x nhân x - 1/6 = 5/18
A)\(\frac{254\cdot399-145}{254+399\cdot253}\)
\(=\frac{\left(253+1\right)\cdot399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+1\cdot399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+399-145}{254+399\cdot253}\)
\(=\frac{253\cdot399+254}{254+399\cdot253}\Rightarrow=1\)
B) X x X - 1/6 = 5/18
x2 = 5/18 + 1/6
x2 = 8/18 = 4/9
x= \(\sqrt{\frac{4}{9}}\) \(=\frac{2}{3}\)
a, \(\dfrac{254\times399-145}{254+399\times253}\)
= \(\dfrac{\left(253+1\right)\times399-`45}{254+399\times253}\)
= \(\dfrac{253\times399+399-145}{253\times399+254}\)
= \(\dfrac{253\times399+254}{253\times399+254}\)
= 1
b, \(\dfrac{5932+6001\times5931}{5932\times6001-69}\)
= \(\dfrac{5932+6001\times5931}{\left(5931+1\right)\times6001-69}\)
= \(\dfrac{5932+6001\times5931}{5931\times6001+6001-69}\)
= \(\dfrac{5932+6001\times5931}{5931\times6001+5932}\)
= 1
254x399-145
------------------
254+399x253
Cái dấu____ là gì hả bn
Ai đổi k nhắn mk nhé
Nhắn chứ ko phải kết bn đâu nha
254 x 399 - 145 101201
----------------------- = ------------- = 1
254 + 399 x 253 101201
Ko chắc chắn đúng . Chúc bn học tốt .
# MissyGirl #