Toán tìm x a,(2x+1):7=2^2+3 b) 450:[41- (2x-5)]=3^2.5 c) (5x-39).7+3=80 09/07/2021 By Eden tìm x a,(2x+1):7=2^2+3 b) 450:[41- (2x-5)]=3^2.5 c) (5x-39).7+3=80
Giải thích các bước giải: $a)(2x+1):7=2^2+3$ $⇔(2x+1):7=7$ $⇔2x+1=49$ $⇔2x=48$ $⇔x=24$ $\text{Vậy $x=24$}$ $b)450:[41-(2x-5)]=3^2.5$ $⇔41-2x+5=450:(3^2.5)$ $⇔46-2x=10$ $⇔2x=36$ $⇔x=18$ $\text{Vậy $x=18$}$ $c)(5x-39).7+3=80$ $⇔(5x-39).7=77$ $⇔5x-39=77:7$ $⇔5x-39=11$ $⇔5x=11+39$ $⇔5x=50$ $⇔x=10$ $\text{Vậy $x=10$}$ Học tốt!!! Trả lời
Các bước giải: $a)$` (2x +1) :7= 2^2 +3` `⇒ (2x +1) :7 = 7` `⇒ 2x +1 = 49` `⇒ 2x = 48` `⇒ x = 24` Vậy `x = 24` —————– $b)$ `450 :[41 – (2x -5)] = (3^2).5` `⇒ 450 :(41 -2x +5) = 45` `⇒ 46 -2x = 10` `⇒ 2x = 36` `⇒ x = 18` Vậy `x = 18` —————– $c)$ `(5x -39).7 +3 = 80` `⇒ (5x -39).7 = 77` `⇒ 5x -39 = 11` `⇒ 5x = 50` `⇒ x = 10` Vậy` x = 10` Trả lời
Giải thích các bước giải:
$a)(2x+1):7=2^2+3$
$⇔(2x+1):7=7$
$⇔2x+1=49$
$⇔2x=48$
$⇔x=24$
$\text{Vậy $x=24$}$
$b)450:[41-(2x-5)]=3^2.5$
$⇔41-2x+5=450:(3^2.5)$
$⇔46-2x=10$
$⇔2x=36$
$⇔x=18$
$\text{Vậy $x=18$}$
$c)(5x-39).7+3=80$
$⇔(5x-39).7=77$
$⇔5x-39=77:7$
$⇔5x-39=11$
$⇔5x=11+39$
$⇔5x=50$
$⇔x=10$
$\text{Vậy $x=10$}$
Học tốt!!!
Các bước giải:
$a)$` (2x +1) :7= 2^2 +3`
`⇒ (2x +1) :7 = 7`
`⇒ 2x +1 = 49`
`⇒ 2x = 48`
`⇒ x = 24`
Vậy `x = 24`
—————–
$b)$ `450 :[41 – (2x -5)] = (3^2).5`
`⇒ 450 :(41 -2x +5) = 45`
`⇒ 46 -2x = 10`
`⇒ 2x = 36`
`⇒ x = 18`
Vậy `x = 18`
—————–
$c)$ `(5x -39).7 +3 = 80`
`⇒ (5x -39).7 = 77`
`⇒ 5x -39 = 11`
`⇒ 5x = 50`
`⇒ x = 10`
Vậy` x = 10`