Toán Tìm x t Z biết a) -12(x-5)+7(3-x)=5 b)30(x+2)-6(x-5)-27x=100 07/07/2021 By Iris Tìm x t Z biết a) -12(x-5)+7(3-x)=5 b)30(x+2)-6(x-5)-27x=100
a) -12(x-5)+7(3-x)=5 ⇔ -12x +60 +21 -7x = 5 ⇔ -12x -7x = 5 -60 -21 ⇔ -19x = -76 ⇔ x = 4 Vậy x= 4 b)30(x+2)-6(x-5)-27x=100 ⇔ 30x +60 -6x +30 -27x = 100 ⇔ 30x -6x -27x = 100 -60 -30 ⇔ -3x = 10 ⇔ x = -10/3 Vậy x= -10/3 Trả lời
a) $-12(x-5) + 7(3-x) = 5$$⇔ -12x + 60 + 21 – 7x = 5$ $⇔ -12x – 7x = 5 – 60 – 21$$⇔ -19x = -76$$⇔ x = ( – 76 ) ÷ ( -19 )$$⇔ x = 4$ b) $30(x+2) -6(x-5)-27x=100$$⇔ 30x + 60 -6x + 30 – 27x = 100$$⇔ 30x – 27x – 6x = 100 – 30 – 60$$⇔ -3x = 10$$⇔ x = \dfrac{-10}{3}$ Trả lời
a) -12(x-5)+7(3-x)=5
⇔ -12x +60 +21 -7x = 5
⇔ -12x -7x = 5 -60 -21
⇔ -19x = -76
⇔ x = 4
Vậy x= 4
b)30(x+2)-6(x-5)-27x=100
⇔ 30x +60 -6x +30 -27x = 100
⇔ 30x -6x -27x = 100 -60 -30
⇔ -3x = 10
⇔ x = -10/3
Vậy x= -10/3
a) $-12(x-5) + 7(3-x) = 5$
$⇔ -12x + 60 + 21 – 7x = 5$
$⇔ -12x – 7x = 5 – 60 – 21$
$⇔ -19x = -76$
$⇔ x = ( – 76 ) ÷ ( -19 )$
$⇔ x = 4$
b) $30(x+2) -6(x-5)-27x=100$
$⇔ 30x + 60 -6x + 30 – 27x = 100$
$⇔ 30x – 27x – 6x = 100 – 30 – 60$
$⇔ -3x = 10$
$⇔ x = \dfrac{-10}{3}$