=>158y=16700

=>y=8350/79

\(y.27+y.42-y.19+y.70=16700\)

\(\Leftrightarrow y\left(27+42-19+70\right)=16700\)

\(\Leftrightarrow y.120=16700\)

\(\Leftrightarrow y=\dfrac{835}{6}\)

A nha em

Chọn A

`A)2/3=x/60`

`=>40/60=x/60`

`=>x=40`

`B)-1/2=y/18`

`=>-9/18=y/18`

`=>y=-9`

`C)3/x=y/35=-36/84`

Mà `-36/84=(-3 xx 12)/(7 xx 12)=-3/7`

`=>3/x=-3/7`

`=>x=-7`

`y/35=-3/7=-15/35`

`=>y=-15`

`D)7/x=y/27=-42/54`

Mà `-42/54=(-7 xx 6)/(9 xx 6)=-7/9`

`=>7/x=-7/9`

`=>x=-9`

`y/27=-7/9=-21/27`

`=>y=-21`

Ông viết rõ ràng đc ko?

1,x=12 hoac 6

2,y=14

ban noi ro dc ko

a) 12/16 = -x/4    <=> 12.4=-x.16   <=> -16x=48    <=> x= -48/16=-3

12/16=21/y    <=> 12.y=16.21    <=>12y=336     <=> y= 336:12    <=> y=28

b)   3/x =-42/70    <=>   -42.x=70.3      <=>  -42x=210    <=> x=210/(-42)=-5

y/35=-42/70   <=> 70.y=-42.35       <=>70y=-1470     <=>  y= -1470: 70=-21

a) Ta có: \(\left|x\right|=42\Rightarrow x=\pm42\)

Nếu x = 42 => A = 42 + 7 + 12 = 61

Nếu x = -42 => A = -42 + 7 + 12 = -23

b) \(\left|x\right|=9\Rightarrow x=\pm9\)

Nếu x = 9 và y = 14 => B = 27 - 9 + 14 = 32

Nếu x = -9 và y = 14 => B = 27 + 9 + 14 = 50

zzzzxeeee

\(\frac{7}{-9}=\frac{-21}{27}=\frac{-42}{54}\)

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