Tìm số nguyên x,biết: a) 12-(3x+4)=38 b) -(5x-7)-62=10 c) 32-|2x+4|=60 Giải giúp em với ạ 21/07/2021 Bởi Reese Tìm số nguyên x,biết: a) 12-(3x+4)=38 b) -(5x-7)-62=10 c) 32-|2x+4|=60 Giải giúp em với ạ
a) 12-(3x+4)=38 =>3x+4=12-38 =>3x+4=-26 =>3x =(-26)-4 =>3x =-30 =>x =(-30)÷3 =>x =-10 b) -(5x-7)-62=10 =>-(5x-7) =10+62 =>-(5x-7) =72 =>-(5x) =72+(-7) =>-(5x) =65 =>-x =65÷(-5) =>-x =-13 c)32-|2x+4|=60 =>|2x+4| =32-60 =>|2x+4| =-28 =>2x+4 =-28 =>2x =(-28)-4 =>2x =-32 =>x =-32÷2 =>x =-16 Bình luận
a) 12-(3x+4)=38 ⇔ 3x+4 =12-38 ⇔ 3x+4 =-26 ⇔ 3x =-26-4 ⇔ 3x =-30 ⇔ x =-30:3 ⇔ x =-10 Vậy x =-10 b) -(5x-7)-62=10 ⇔-5x+7 =10+62 ⇔-5x+7 =72 ⇔-5x =72-7 ⇔-5x =65 ⇔ x =65:(-5) ⇔ x =-13 Vậy x =-13 c) 32-|2x+4|=60 ⇔|2x+4|=32-60 ⇔|2x+4|=-28 ⇔2x+4 =-28 ⇔2x =-28-4 ⇔2x =-32 ⇔x =-32:2 ⇔x =-16 Vậy x=-16. Bình luận
a) 12-(3x+4)=38
=>3x+4=12-38
=>3x+4=-26
=>3x =(-26)-4
=>3x =-30
=>x =(-30)÷3
=>x =-10
b) -(5x-7)-62=10
=>-(5x-7) =10+62
=>-(5x-7) =72
=>-(5x) =72+(-7)
=>-(5x) =65
=>-x =65÷(-5)
=>-x =-13
c)32-|2x+4|=60
=>|2x+4| =32-60
=>|2x+4| =-28
=>2x+4 =-28
=>2x =(-28)-4
=>2x =-32
=>x =-32÷2
=>x =-16
a) 12-(3x+4)=38
⇔ 3x+4 =12-38
⇔ 3x+4 =-26
⇔ 3x =-26-4
⇔ 3x =-30
⇔ x =-30:3
⇔ x =-10
Vậy x =-10
b) -(5x-7)-62=10
⇔-5x+7 =10+62
⇔-5x+7 =72
⇔-5x =72-7
⇔-5x =65
⇔ x =65:(-5)
⇔ x =-13
Vậy x =-13
c) 32-|2x+4|=60
⇔|2x+4|=32-60
⇔|2x+4|=-28
⇔2x+4 =-28
⇔2x =-28-4
⇔2x =-32
⇔x =-32:2
⇔x =-16
Vậy x=-16.