giúp mik
5/7 x y= 2/3 2/9 + y=1+2/3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Lớp học online hay j mà lắm giáo viên thế🤔🤔 Lớp học của tri thức à?
( 2 x y + 2/15 ) x 3 = 4/5
( 2 x y + 2/15 ) = 4/5 : 3
( 2 x y + 2/15 ) = 4/15
2 x y = 4/15 - 2/15
2 x y = 2/15
y = 2/15 :2
y = 1/15
(2 x y + 2/15) x 3 = 4/5
2 x y + 2/15) = 4/5 : 3
2 x y + 2/15 = 4/15
2 x y = 4/15 - 2/15
2 x y = 2/15
y = 2/15 : 2
y = 1/15
7/9 x (2 - 1/3 x y) = 14/15
(2 - 1/3 x y) = 14/15 : 7/9
(2 - 1/3 x y) = 6/5
2 - y = 6/5 x 1/3
2 - y = 2/5
y = 2/5 + 2
y = 12/5
4/21 + 5 x y - 8/7 = 1/3
4/21 + 5 x y = 1/3 + 8/7
4/21 + 5 x y = 31/21
5 x y = 31/21 - 4/21
5 x y = 9/7
y = 9/7 : 5
y = 9/35
7/12 x y - 3/12 x y = 5
y x (7/12 - 3/12) = 5
y x 1/3 = 5
y = 5 : 1/3
y = 15
a) (x + 1).(y + 2)=7
Có 4 TH xảy ra :
TH1 : x + 1 = 1 => x = 0
y + 2 = 7 => y = 5
TH2 : x + 1 = 7 => x = 6
y + 2 = 1 => y = -1
TH3 : x + 1 = -1 => x = -2
y + 2 = -7 => y = -9
TH4 : x + 1 = -7 => x = -8
y + 2 = -1 => y = -3
b) x(y - 3) = 12
Có 12 TH xảy ra :
TH1 : x = 1
y - 3 = 12 => y = 15
TH2 : x = 12
y - 3 = 1 => y = 4
TH3 : x = 2
y - 3 = 6 => y = 9
TH4 : x = 6
y - 3 = 2 => y = 5
TH5 : x = 3
y - 3 = 4 => y = 7
TH6 : x = 4
y - 3 = 3 => y = 6
TH7 : x = -1
y - 3 = -12 => y = -9
TH8 : x = -12
y - 3 = -1 => y = 2
TH9 : x = -2
y - 3 = -6 => y = -3
TH10 : x = -6
y - 3 = -2 => y = 1
TH11 : x = -3
y - 3 = -4 => y = -1
TH12 : x = -4
y - 3 = -3 => y = 0
c) (x - 3)(y - 3) = 9
Có 6 TH xảy ra :
TH1 : x - 3 = 1 => x = 4
y - 3 = 9 => y = 12
TH2 : x - 3 = 9 => x = 12
y - 3 = 1 => y = 4
TH3 : x - 3 = -1 => x = 2
y - 3 = -9 => y = -6
TH4 : x - 3 = -9 => x = -6
y - 3 = -1 => y = 2
TH5 : x - 3 = 3 => x = 6
y - 3 = 3 => y = 6
TH6 : x - 3 = -3 => x = 0
y - 3 = -3 => y = 0
(x + 1)(y + 2) = 7 = 7.1 = 1.7 = (-1).(-7)= (-7)(-1)
x + 1 = 7 => x= 6
y + 2 = 1 => y = -1
x + 1 =1 => x= 0
y + 2 = 7=> y = 5
x + 1 = -1 => x= -2
y + 2 = -7 => y = -9
x + 1= -7 => x = -8
y + 2 = -1 => y = -3
Tương tự
a) y + 3/7 x 21/9 = 5
y + 3/7 x 7/3 = 5
y + 1 = 5
y = 4
b) y x 3/5 - 1/2 = 4/5
y x 3/5 = 4/5 + 1/2
y x 3/5 = 13/10
y = 13/6
c) 9/8 - y + 2/5 = 1/4
y - 2/5 = 9 /8 - 1/4
y - 2/5 = 7/8
y = 51/40
d) y - 6/5 : 2/3 = 5/6
y - 9/5 = 5/6
y = 79/30
e) y : 7/8 + 3/4 = 7/4
y : 7/8 = 1
y = 7/8
\(\dfrac{8}{9}\) : ( 2 - 3 \(\times\) y) = \(\dfrac{5}{3}\)
2 - 3 \(\times\) y = \(\dfrac{8}{9}\) : \(\dfrac{5}{3}\)
2 - 3 \(\times\) y = \(\dfrac{8}{15}\)
3 \(\times\) y = 2 - \(\dfrac{8}{15}\)
3 \(\times\) y = \(\dfrac{22}{15}\)
y = \(\dfrac{22}{15}\) : 3
y = \(\dfrac{22}{45}\)
\(\text{ x . (x - 3) = 0}\)
\(\Rightarrow\orbr{\begin{cases}x=0\\x-3=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=0\\x=3\end{cases}}\)
vậy_______
1 ) 5 - ( 10 - x ) = 7
10 - x = 5 - 7
10 - x = - 2
x = 10 - ( - 2 )
x = 12
Vậy x = 12
a, y \(\times\) \(\dfrac{4}{3}\) = \(\dfrac{16}{9}\)
y = \(\dfrac{16}{9}\) : \(\dfrac{4}{3}\)
y = \(\dfrac{4}{3}\)
b, ( y - \(\dfrac{1}{2}\)) + 0,5 = \(\dfrac{3}{4}\)
y - 0,5 + 0,5 = \(\dfrac{3}{4}\)
y = \(\dfrac{3}{4}\)
c, \(\dfrac{4}{5}-\dfrac{2}{5}y\) = 0,2
0,8 - 0,4y = 0,2
0,4y = 0,8 - 0,2
0,4y = 0,6
y = 1,5
d, (y + \(\dfrac{3}{4}\)) \(\times\) \(\dfrac{5}{7}\) = \(\dfrac{10}{9}\)
y + \(\dfrac{3}{4}\) = \(\dfrac{10}{9}\) : \(\dfrac{5}{7}\)
y + \(\dfrac{3}{4}\) = \(\dfrac{14}{9}\)
y = \(\dfrac{14}{9}\) - \(\dfrac{3}{4}\)
y = \(\dfrac{29}{36}\)
e, y : \(\dfrac{5}{4}\) = \(\dfrac{9}{5}\) + \(\dfrac{1}{2}\)
y : \(\dfrac{5}{4}\) = \(\dfrac{23}{10}\)
y = \(\dfrac{23}{10}\)
y = \(\dfrac{23}{8}\)
f, y \(\times\) \(\dfrac{1}{2}\) + \(\dfrac{3}{2}\) \(\times\) y = \(\dfrac{4}{5}\)
y \(\times\) ( \(\dfrac{1}{2}+\dfrac{3}{2}\)) = \(\dfrac{4}{5}\)
2y = \(\dfrac{4}{5}\)
y = \(\dfrac{2}{5}\)
a: =(x-y)^2+2(x-y)
=(x-y)(x-y+2)
c: =(x-3)(x+3)+(x-3)^2
=(x-3)(x+3+x-3)
=2x(x-3)
d: =(x+3)(x^2-3x+9)-4x(x+3)
=(x+3)(x^2-7x+9)
e: =(x^2-8x+7)(x^2-8x+15)-20
=(x^2-8x)^2+22(x^2-8x)+85
=(x^2-8x+17)(x^2-8x+5)
y = 2/3 : 5/7
y = 14/15
2/9 + y = 5/3
y = 5/3 - 2/9
y = 13/9
5/7 x y= 2/3
y = 2/3 : 5/7
y = 14/15
2/9 + y=1+2/3
2/9 + y= 5/3
y = 5/3 - 2/9
y = 13/9