Question

tìm y

a,21x(34-y)=42

b,(y-47)-115=0

c,2y+3y=1505

d,(2y+1)x2907=8721

e,(4y-16):1905=60

Answer 1

`a, 21 xx (34 - y) = 42`

`=> 34 - y = 42 : 21`

`=> 34 - y = 2`

`=> y = 34 - 2`

`=> y = 32`

Vậy `y = 32`

`b, (y - 47) - 115 =0`

` => y - 47 = 0 + 115`

` => y - 47 = 115`

` => y = 115 + 47`

` => y = 162`

Vậy `y = 162`

`c, 2y + 3y = 1505`

` => 5y = 1505`

` => y = 1505 : 5`

` => y = 301`

Vậy `y = 301`

`d, (2y + 1) xx 2907 = 8721`

` => 2y + 1 = 8721 : 2907`

` => 2y + 1 = 3`

` => 2y = 3 - 1`

` => 2y = 2`

` => y = 2:2`

` => y = 1`

Vậy `y = 1`

\(e,\left(4y-16\right):1905=60\)

`=> 4y - 16 = 60 xx 1905`

`=> 4y - 16 = 114300`

`=> 4y = 114300 + 16`

`=> 4y = 114316`

`=> y = 114316 : 4`

`=> y = 28579`

Vậy `y = 28579`