Question

[Cô Bé Song Ngư]

Tìm x \(\in\)z , biết :

a, ( 15 - x ) + ( x - 12 ) = 7 - ( -8 + x)

b x - ngoặc nhọn 55 - mở ngoặc vuông 49 + ( - 28 - x) = 13 - mở ngoặc nhọn 47 + mở ngoặc vuông 25 - ( 32 - x )

c, | x - 10 | - | -12| = 4

Answer 1

[Cold Wind]

a) \(\left(15-x\right)+\left(x-12\right)=7-\left(-8+x\right)\)

\(15-x+x-12=7+8-x\)

\(x=12\)

b) \(x-\left\{55-\left[49+\left(-28-x\right)\right]\right\}=13-\left\{47+\left[25-\left(32-x\right)\right]\right\}\)

\(x-55+49-28-x=13-47-25+32-x\)

\(x=7\)

Answer 2

[Uzumaki Naruto]

\(a,\left(15-x\right)+\left(x-12\right)=7-\left(-8+x\right)\)

\(15-x+x-12=7+8-x\)

\(15-x=3\)

\(x=12\)

\(b,x-\left\{55-\left[49+\left(-28-x\right)\right]\right\}=13-\left\{47+\left[25-\left(32-x\right)\right]\right\}\)

\(x-\left[55-\left(49-28-x\right)\right]=13-\left[47+\left(25-32+x\right)\right]\)

\(x-\left(55-49+28+x\right)=13-\left(47+25-32+x\right)\)

\(x-\left(34+x\right)=13-\left(40+x\right)\)

\(x-34-x=13-40-x\)

\(-27-x=-34\)

\(x=-27--34\)

\(x=7\)

\(c,\left|x-10\right|-\left|-12\right|=4\)

\(\left|x-10\right|-12=4\)

\(\left|x-10\right|=16\)

\(\Rightarrow x-10=16\)hoặc   \(x-10=-16\)

\(x=26\)hoặc   \(x=-6\)