Giúp mik vs:
Tìm số nguyên x, y , biết:
A, 5x + 17 = 2
B, x – 1/4 = 2/3 . 9/8
C, 3/x = y/28 = -39/91
Giúp mik vs: Tìm số nguyên x, y , biết: A, 5x + 17 = 2 B, x – 1/4 = 2/3 . 9/8 C, 3/x = y/28 = -39/91
By Kylie
By Kylie
Giúp mik vs:
Tìm số nguyên x, y , biết:
A, 5x + 17 = 2
B, x – 1/4 = 2/3 . 9/8
C, 3/x = y/28 = -39/91
Đáp án + giải thích bước giải :
`a) 5x + 17 = 2`
`-> 5x = -15`
`-> x = -3`
`b) x- 1/4 = 2/3 . 9/8`
`-> x – 1/4 = 3/4`
`-> x = 1`
`c) 3/x = y/28 = (-39)/91`
Có : `3/x = (-39)/91`
`-> 3 . 91 = -39x`
`-> -39x = 273`
`-> x = -7`
Có : `y/28 = (-39)/91`
`-> 91y = 28 . (-39)`
`-> 91y = -1092`
`-> y = -12`
$A)5x+17=2$
$5x=2-17$
$5x=-15$
$x=-15:5$
$x=-3$
$B)$ $x-$$\frac{1}{4}$ $=$ $\frac{2}{3}$ . $\frac{9}{8}$
$x-$$\frac{1}{4}$ $=$ $\frac{3}{4}$
$x=$ $\frac{3}{4}$ $+$ $\frac{1}{4}$
$x=1$
$C)$ $\frac{3}{x}$ $=$ $\frac{y}{28}$ $=$ $\frac{-39}{91}$
$⇒$ $\frac{3}{x}$ $=$ $\frac{-39}{91}$ $;$ $\frac{y}{28}$ $=$ $\frac{-39}{91}$
$+)$ $\frac{3}{x}$ $=$ $\frac{-39}{91}$
$⇒$ $3.91=x.(-39)$
$⇒$ $273=-39x$
$⇒$ $x=273:(-39)$
$⇒$ $x= -7$
$+)$ $\frac{y}{28}$ $=$ $\frac{-39}{91}$
$⇒$ $y.91=28.(-39)$
$⇒$ $91y = -1092$
$⇒$ $y= -1092:91$
$⇒$ $y = -12$
$\text{Vậy}$ $x=-7;y=-12$
$@YuuSaji$