tìm x
X*5439=54*5438+54 =
7899*X=102*7890+102+102*8=
làm nhanh nha
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
(145 x 99 + 145 ) - ( 143 x 102 – 143 × 2 ) + 54 x 47 - 47 x 53 - 20 - 27
= 145 × (99 + 1) – 143 × (102 – 2) + 47 × (54 – 53) – (20 + 27)
= 145 × 100 – 143 × 100 + 47 × 1 – 47
= 100 × (145 – 143) + (47 – 47)
= 100 × 2 + 0
= 200
(145 x 99 + 145 ) - ( 143 x 102 – 143 × 2 ) + 54 x 47 - 47 x 53 - 20 - 27
= 145 × (99 + 1) – 143 × (102 – 2) + 47 × (54 – 53) – (20 + 27)
= 145 × 100 – 143 × 100 + 47 × 1 – 47
= 100 × (145 – 143) + (47 – 47)
= 100 × 2 + 0
= 200
(145 x 99 + 145 ) - ( 143 x 102 – 143 × 2 ) + 54 x 47 - 47 x 53 - 20 - 27
= 145 × (99 + 1) – 143 × (102 – 2) + 47 × (54 – 53) – (20 + 27)
= 145 × 100 – 143 × 100 + 47 × 1 – 47
= 100 × (145 – 143) + (47 – 47)
= 100 × 2 + 0
= 200
= 145 x (99+1) - 143 x ( 102-2) + 47 x ( 54 - 53) -20-27
= 145 x 100 - 143 x 100 + 47 x 1 -20-27
= 100 x ( 145 - 143 ) + 47 - 20 - 27
= 200 + 47 - 20 - 27
= 200
( 158 x 129 - 158 x 39 ) : 180
= [ 158 x ( 129 - 39 ) ] : 180
= [ 158 x 90 ] : 180
= 14220 : 180
= 79
1) ( 158 x 129 - 158 x 39 ) : 180
= [158 x (129 - 39 ) ] : 180
= 158 x 90 : 180
= 158 x ( 90 : 180 )
= 158 x 1/2
= 158 : 2
= 79.
2)102- 96 +90-84+78-72+66-60+54-48
= ( 102 - 72 ) + ( -96 + 66 ) + ( 90 - 60 ) + ( -84 + 54 ) + ( 78 - 48 )
= 30 - 30 + 30 - 30 + 30 = 30
A) 145 x (99 + 1) - 143 x (102 - 1)
= 145 x 100 - 143 x 101 = 145 x 100 - 143 x (100 + 1)
= 100 x (145 - 143) - 143
= 200 - 143 = 57
B) 54 x 47 - 47 x 53 - 20 - 27
= 47 x (54 - 53) - (20 + 27)
= 47 x 1 - 47 = 0
\(\text{10^2 - [60: (5^6 : 5^4 - 3.5) ]}\\ =100-\left[60:\left(5^2-15\right)\right]\\ =100-\left[60:10\right]\\ =100-6\\ =94\)
\(x\cdot5439=54\cdot5438+54\)
\(x\cdot5439=54\cdot5438+54\cdot1\)
\(x\cdot5439=54\cdot\left(5438+1\right)\)
\(x\cdot5439=54\cdot5439\)
\(\Rightarrow x=54\)
\(7899\cdot x=102\cdot7890+102+102\cdot8\)
\(7899\cdot x=102\cdot7890+102\cdot1+102\cdot8\)
\(7899\cdot x=\left(7890+1+9\right)\cdot102\)
\(7899\cdot x=7899\cdot102\)
\(\Rightarrow x=102\)