a) 5x + 3x = 36 : 33.4 + 12
4x + 2x = 68 – 219 : 216
a) 5x + x = 39 – 311:39
b) 7x – x = 521 : 519 + 3.22 - 70
c) 7x – 2x = 617: 615 + 44 : 11
a: \(\Leftrightarrow6x=30\)
hay x=5
b: \(\Leftrightarrow6x=25+12-1=36\)
hay x=6
a) 5x + 3x = 36 : 33.4 + 12
4x + 2x = 68 – 219 : 216
a) 5x + x = 39 – 311:39
b) 7x – x = 521 : 519 + 3.22 - 70
c) 7x – 2x = 617: 615 + 44 : 11
a: \(\Leftrightarrow8x=108+12=120\)
hay x=15
b: \(\Leftrightarrow6x=60\)
hay x=10
a) 5x + 3x = 120
x . (5+3)= 120
x . 8 = 120
x = 120 : 8
x = 15
c) 7x - 2x = 40
x .(7-2)= 40
x . 5 = 40
x = 40 : 5
x = 8
tính bằng cách thuận nhất
1237 x 12 + 1237 x 34 + 1237 + 1237 x 53
( 100 - 99 + 97 - 80 + 15 ) x ( 16 - 2 x 8 )
1237 x (12 + 34 + 1 + 53)
= 1237 x 100
= 123700
(100-99+97-80+15) x (16 - 16)
= 0 x (100-99+97-80+15) =0
Tìm x, biết
a) (x-14)-20 = 0;
b) 25 - ( 2.x +10) = 5;
c) 315 - (135 - x) = 215;
d) 128 + ( 202 - x ) = 330;
e) x - 320:32 = 25.16;
f) ( x - 120) .9 = 450.
a) x = 34
b) x= 5
c) x = 35
d) x = 0
e) x = 410
f) x= 170
Tìm x ∈ ℤ ,biết:
a ) 5 2 + − 11 2 < x < 8 3 + 5 6 ; b ) 1 5 + 2 35 < x 35 < − 3 7 + 4 5 ;
c ) 1 2 + − 3 5 + 1 10 ≤ x ≤ 8 3 + 14 6 ; d ) 1 4 + 5 12 + − 5 3 ≤ x ≤ 11 5 + − 5 10 + 1 2
a) x ∈ {-2;-1;;0;1;2;3}
b) x ∈ {10;11;12}
c) x ∈ {0;1;2;3;4;5}
d) x ∈ {-1;0;1;2}
a.9700 : 100 + 36 x 12
b.(160 x 5 - 25 x 4) : 4
c.108 x (23 + 7)
d.215 x 86 + 215 x 14
e.53 x 128 - 43 x 128
9700 : 100 + 36 x 12 = 529
(160 x 5 - 25 x 4) : 4= 175
108 x (23 + 7) = 3240
215 x 86 + 215 x 14 = 21500
3 x 128 - 43 x 128= -5120
Tìm x
a) x + 3 4 = 5 3 b) x - 1 6 = 5 12
5 Tìm số nguyên x , biết
a) x + 49 = - 97
b) x - 53 = - 61
c) 158 - x = - 92
d) - 218 + x = 147
e) - 135 - x = 41
f) x + 215 = - 315
g) 148 - x = 942
h) 47 - ( - x ) = 18
i) - x + 45 = - 14
x ởa,b,c,d,e,f,g,h,i lần lượt là: -146; -8; -250; -365; -185; -530; -794; -29; 59
Tìm x:
a) (x-19).(x+21)=0
b)(53-x).(41+x)=0
\(a.\)
\(\left(x-19\right)\left(x+21\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-19=0\\x+21=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=19\\x=-21\end{matrix}\right.\)
\(S=\left\{19,-21\right\}\)
\(b.\)
\(\left(53-x\right)\left(41+x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}53-x=0\\41+x=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=53\\x=-41\end{matrix}\right.\)
\(S=\left\{53,-41\right\}\)
Tìm x:
a) (x-19).(x+21)=0
<=>\(\left\{{}\begin{matrix}x-19=0< =>x=19\\x+21=0< =>x=-21\end{matrix}\right.\)
Vậy pt trên có tập nghiệm là: S={19;-21}
b)(53-x).(41+x)=0
<=>\(\left\{{}\begin{matrix}53-x=0< =>x=53\\41+x=0< =>x=-41\end{matrix}\right.\)
Vậy pt trên có tập nghiệm là S={53;-41}
a) x là 19 hoặc -21
b) x là 53 hoặc-41
cho tớ tim nhá
