Tìm x,biết :
a)\(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
b)x+(x+1)+(x+2)+...+(x+30)=1240
c)11-(-53+x)=97
d)-(x+84)+213=-16
\(\text{Tìm x, biết:}\)
\(a\)) \(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(b\)) \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)
\(c\)) \(11-\left(-53+x\right)=97\)
\(d\)) \(-\left(x+84\right)+213=-16\)
Bài 2 : Tìm x , biết :
a, \(\left(19x+2\cdot5^2\right)\text{ : }14=\left(13-8\right)^2-4^2\)
b, \(x+\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+30\right)=1240\)
c, \(11-\left(-53+x\right)=97\)
d, \(-\left(x+84\right)+213=-16\)
e, \(13-12+11+10-9+8-7-6+5-4+3+2-1=x\)
\(a,\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(\Leftrightarrow\left(19x+50\right):14=5^2-4^2\)
\(\Leftrightarrow\left(19x+50\right):14=9\)
\(\Leftrightarrow19x+50=126\)
\(\Leftrightarrow19x=76\Leftrightarrow x=4\)
b) x + ( x + 1 ) + ( x + 2 ) + ... + ( x + 30 ) = 1240
x + x + 1 + x + 2 + ... + x + 30 = 1240
( x + x + ... + x ) + ( 1 + 2 + ... + 30 ) = 1240
Số số hạng là : ( 30 - 1 ) : 1 + 1 = 30 ( số )
Tổng là : ( 30 + 1 ) . 30 : 2 = 465
=> 31x + 465 = 1240
=> 31x = 775
=> x = 25
Vậy........
c) 11 - ( -53 + x ) = 97
11 + 53 - x = 97
64 - x = 97
x = 64 - 97
x = -33
a) (19x+2.5^2):14=(13-8)^2-4^2
b) x+(x+1)+(x+2)+...+(x+30)=1240
c) 11-(-53+x)=97
d) -(x+84)+213=-16
(3.4.2^16)^2/11.2^13.4^11-16^9.Tính bằng cách hợp lý
Câu 2:
a,(19x+2.5^2):14=(13-8)^2-4^2
b,x+(x+1)+(x+2)+...+(x+30)=1204
c,11-(-53+x)=97
d,-(x+84)+213=-16
Tìm x
a) \(\left(19.x+2.5^1\right):14=\left(13-8\right)^2-4^2\)
b) \(-\left(x+84\right)+213=-16\)
\(\left(19x+2.5^1\right):14=\left(13-8\right)^2-4^2.\)
\(\left(19x+10\right):14=5^2-4^2\)
\(\left(19x:4\right)+\left(10:4\right)=25-16\)
\(\left(19x:4\right)+\frac{5}{2}=9\)
\(19x:4=9-\frac{5}{2}\)
\(19x:4=\frac{13}{2}\)
\(19x=\frac{13}{2}.4=26\)
\(x=\frac{26}{19}\)
B/ \(-\left(x+84\right)+213=\left(-16\right).\)
\(-x-84+213=-16\)
\(-x+129=-16\)
\(-x=\left(-145\right)\)
\(\Rightarrow x=145\)
Câu hỏi : Tìm x
a, (19x+2.5 mũ 2):14 = ( 13 - 8) mũ 2 - 4 mũ 2
b, x + ( x + 1 ) + ( x + 2 ) +...+ ( x + 30 )= 1240
c, 11- ( -53 + x ) = 97
d,-(x + 81) + 213 = -16
a) \(\left(19x+2\cdot5^2\right):14=\left(13-8\right)^2-4^2\)
\(\left(19x+2\cdot5^2\right):14=9\)
\(19x+2\cdot5^2=9\cdot14=126\)
\(19x+50=126\)
\(19x=126-50=76\)
\(x=\frac{76}{19}=4\)
b) \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)
\(\left(x+x+..+x\right)+\left(1+2+3+...+30=1240\right)\)(31 chữ số x)
\(31x+\frac{30\cdot31}{2}=1240\Leftrightarrow31x+465=1240\)
\(31x=1240-465=775\)
\(x=\frac{775}{31}=25\)
c) \(11-\left(-53+x\right)=97\)
\(11+53-x=97\Leftrightarrow64-x=97\)
\(x=64-97=-33\)
d) \(-\left(x+81\right)+213=-16\)
\(-x-81+213=-16\)
\(-x+132=-16\)
\(-x=-16-132=-148\)
\(x=148\)
..........
a) \(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
b) \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)
c) \(|x+7|=20+5.\left(-3\right)\)
a, (19x+2.52) : 14 = (13-8)2 - 42
(19x + 2.25) : 14 = 52 - 42
(19x + 50) : 14 = 25 - 16
(19x + 50) : 14 = 9
19 x + 50 = 9.14
19x + 50 = 126
19x = 126 - 50
19x = 76
x = 76 : 19
x = 4
vậy____
b) x + (x + 1) + (x + 2) + (x + 3)+.....+(x+30) = 1240
(x+x+x+...+x) + (1+2+3+...+30) = 1240
31x + 465 = 1240
31x = 1240 - 465
31x = 775
x = 775 : 31
x = 25
vậy____
c) |x + 7| = 20 + 5.(-3)
|x + 7| = 20 + (-15)
|x + 7| = 5
\(\Rightarrow\orbr{\begin{cases}x+7=5\\x+7=-5\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=5-7\\x=-5-7\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=-2\\x=-12\end{cases}}\)
vậy_____
Tìm x biết:\(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(\Rightarrow\left(19x+50\right):14=25-16\)
\(\Rightarrow19x+50=9.14=126\)
\(\Rightarrow19x=76\)
\(\Rightarrow x=76:19=4\)
(19x+2.5²):14 =(13-8)²-4²
(19x + 50):14 = 5²-4²
(19x + 50):14 = 9
19x + 50 = 9.14
19x+50 = 126
19x =76
x =76:19
x =4
Chúc các bn học tốt ah🥰🥰
Tìm x biết:
\(a\)) \(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(b\)) \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)
\(c\)) \(11-\left(-53+x\right)=97\)
c,11-(-53+x)=97
-53+x=11-97
-53+x= -86
x = -86-(-53)
x= -33