Bài 1: a) 5x – 2 ³ = 3 ³ b) 7x – 13 = 2 ² . 3 ² c) ( 3x – 9 ) . 12 = 3 ² . 2 ³ 10/07/2021 Bởi Savannah Bài 1: a) 5x – 2 ³ = 3 ³ b) 7x – 13 = 2 ² . 3 ² c) ( 3x – 9 ) . 12 = 3 ² . 2 ³
5x – 2^3 = 3^3 5x – 8 = 27 5x = 27 + 8 5x = 35 x = 35 ÷ 5 x = 7 7x – 13 = 2^2 . 3^2 7x – 13 = 4 . 9 7x – 13 = 36 7x = 36 + 13 7x = 49 x = 49 ÷ 7 x = 7 ( 3x – 9 ).12= 3^2.2^3 ( 3x – 9 ).12= 9 . 8 ( 3x – 9 ).12= 72 (3x – 9 ) = 72 ÷ 12 ( 3x – 9 ) = 6 3x = 6+ 9 3x = 15 x = 15 ÷ 3 x = 5 Bình luận
a) $5x-2^3=3^3$ $↔5x-8=27$ $↔5x=35$ $→x=7$ b) $7x-13=2^2.3^2$$↔7x-13=4.9=36$ $↔7x=49$ $↔x=7$ c) $(3x-9).12=3^2.2^3$ $↔(3x-9).12=9.8=72$ $↔3x-9=6$ $↔3x=15$ $↔x=5$ Bình luận
5x – 2^3 = 3^3
5x – 8 = 27
5x = 27 + 8
5x = 35
x = 35 ÷ 5
x = 7
7x – 13 = 2^2 . 3^2
7x – 13 = 4 . 9
7x – 13 = 36
7x = 36 + 13
7x = 49
x = 49 ÷ 7
x = 7
( 3x – 9 ).12= 3^2.2^3
( 3x – 9 ).12= 9 . 8
( 3x – 9 ).12= 72
(3x – 9 ) = 72 ÷ 12
( 3x – 9 ) = 6
3x = 6+ 9
3x = 15
x = 15 ÷ 3
x = 5
a) $5x-2^3=3^3$
$↔5x-8=27$
$↔5x=35$
$→x=7$
b) $7x-13=2^2.3^2$
$↔7x-13=4.9=36$
$↔7x=49$
$↔x=7$
c) $(3x-9).12=3^2.2^3$
$↔(3x-9).12=9.8=72$
$↔3x-9=6$
$↔3x=15$
$↔x=5$