BÀI 1 A= -1500 – {5^3 .2^3 -11[7^2-5.2^3(11^2-121)]} BÀI 2 a 15 – x=4x – 59 b 7x – 4 = 20 + 3x c x + 15 = 20 -4x d 5 ( x – 6 ) – 2 ( x + 3 ) = 12

0 bình luận về “BÀI 1 A= -1500 – {5^3 .2^3 -11[7^2-5.2^3(11^2-121)]} BÀI 2 a 15 – x=4x – 59 b 7x – 4 = 20 + 3x c x + 15 = 20 -4x d 5 ( x – 6 ) – 2 ( x + 3 ) = 12”

1. Bài $1$.

   $A= -1500 – {5^3 .2^3 -11[7^2-5.2^3(11^2-121)]}$

   $A = -1500 – {125.8 – 11.[49 – 5.2^3.(121-121)]}$

   $A = -1500 – [1000 – 11.(49-0)]$

   $A = -1500 – (1000 – 539)$

   $A = -2500 + 539$

   $A = -1961$.

   Bài $2$.

   $a$) $15-x = 4x-59$

   $⇔ 4x+x = 15 + 59$

   $⇔ 5x = 74$

   $⇔ x = \dfrac{74}{5}$. 

   $b$) $7x-4 = 20+3x$

   $⇔ 7x-3x = 20+4$

   $⇔ 4x = 24$

   $⇔ x = 6$.

   $c$) $x+15 = 20-4x$

   $⇔ x+4x = 20-15$

   $⇔ 5x=5$

   $⇔ x=1$.

   $d$) $5(x-6) – 2(x+3) = 12$

   $⇔ 5x – 30 – 2x – 6 = 12$

   $⇔ 3x – 36 = 12$

   $⇔ 3x = 48$

   $⇔ x = 16$.

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2. Tham khảo

    `1) A=-1500-{5^3.2^3-11[7^2-5.2^3(11^2-121)]}`

   `⇒A=-1500-{10^3-11[49-5.8.0]}`

   `⇒A=-1500-{1000-11[49-0]`

   `⇒A=-1500-{1000-539}`

   `⇒A=-1500-{461}`

   `⇒A=-1961`

   `2) `

   `a) 15-x=4x-59`

   `⇒4x-59-15+x=0`

   `⇒5x-74=0`

   `⇒5x=74`

   `⇒x=\frac{74}{5}`

   `b) 7x-4=20+3x`

   `⇒7x-4-20-3x=0`

   `⇒4x-24=0`

   `⇒4x=24`

   `⇒x=6`

   `c) x+15=20-4x`

   `⇒x+15-20+4x=0`

   `⇒5x-5=0`

   `⇒5x=5`

   `⇒x=1`

   `d) 5(x-6)-2(x+3)=12`

   `⇒5x-30-2x-6=12`

   `⇒3x-36=12`

   `⇒3x=48`

   `⇒x=16`

   `\text{©CBT}`

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