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130-[5.(9-x)+43]=47
5.(9-x)+43=130-47
5.(9-x)+43=83
5.(9-x)=83-43
5.(9-x)=40
9-x=40:5
9-x=8
x=9-8
x=1
\(130-\left[5\times\left(9-x\right)+43\right]=47\)
\(\Rightarrow\left[5\times\left(9-x\right)+43\right]=130-47\)
\(\Rightarrow\left[5\times\left(9-x\right)\right]=83\)
\(\Rightarrow\left(9-x\right)=83\div5\)
\(\Rightarrow\left(9-x\right)=\frac{83}{5}\)
\(\Rightarrow x=9-\frac{83}{5}\)
\(\Rightarrow x=-\frac{38}{5}\)
a.1+3+5+7+...+2x+1=225
[(2x+1-1):2+1]x(2x+1+1):2=225
(x+1)x(2x+2):2=225
(x+1)x(x+1)=225
(x+1)2=225
(x+1)2=152
x+1=15
x=14
_______________
b. 130-[5.(9-x)+43]=47
5.(9-x)+43=83
5.(9-x)=40
9-x=8
x=1
_______________
c.16x<324
24x<220
=>x∈{0;1;2;3;4}
a: =>(x+1)^2=225
=>x+1=15
=>x=14
b: =>[5*(9-x)+43]=130-47=83
=>5(9-x)=40
=>9-x=8
=>x=1
c: =>2^4x<2^20
=>4x<20
=>0<x<5
a, 24.( 5 - 178 ) + 178 .(10 + 24)
= 24.5 - 24 .178 + 178 .10 + 178.24
= (24.5 + 178.10) -( 24.178 - 178.24)
=(120 + 1780) - 0
= 1900
b ,29.(-101)
= 29.( -100 -1)
= - 2900 - 29
= -2929
c, (-56 + 130) - (43 - 56) - (-20 - 43)
= -56 + 130 - 43 + 56 + 20 + 43
= (-56 + 56) - (43 - 43) + ( 130 + 20)
= 0 - 0 + 150
= 150
a , 130 - [ 5 . ( 9 - x ) + 43 ] = 47
[ 5 . ( 9 - x ) + 43 ] = 130 - 47
[ 5 . ( 9 - x ) + 43 ] = 83
5 . ( 9 - x ) = 83 - 43
5 . ( 9 - x ) = 40
9 - x = 40 : 5
9 - x = 8
x = 9 - 8
x = 1
b , [ 2 .( 70 - x ) + 23 . 32 ] : 2 = 46
[ 2 . ( 70 - x ) + 8 . 9 ] : 2 = 46
[ 2 . ( 70 - x ) + 72 ] : 2 = 46
[ 2 . ( 70 - x ) + 72 ] = 92
( 70 - x ) + 72 = 92 : 2
( 70- x ) + 72 = 46
( 70 - x ) = 46 - 72
70 - x = - 26
x = 70 - ( - 26 )
x = 70 + 26
x = 96
`@` `\text {Ans}`
`\downarrow`
`a)`
`-(-18 + 45) - (18 + 55)`
`= 18 - 45 - 18 - 55`
`= (18 - 18) - (45 + 55)`
`= -100`
`b)`
`24. (5 - 178) + 178 . (10 + 24)`
`= 24.5 - 24.178 + 178. 10 + 178. 24`
`= 24.5 + 178.(-24 + 10 + 24)`
`= 24.5 + 178.10`
`=120 + 1780`
`=``1900`
`c)`
`29.(-101)`
`= -2929`
`d)`
\((- 56 + 130) – (43 – 56) – (- 20 – 43)\)
`= -56 + 130 - 43 + 56 + 20 + 43`
`= (56 - 56) + (130 + 20) + (-43+43)`
`= 150`
9 + 130 + 43 x 5 = 9 + 130 + 215 = 139 + 215 = 354
9 + 130 + 43 × 5 =354