Question

Rezolvării ecuatiile:a)5x+3 (x-6)=7x+13
b)6x+4 (c-8)=9x+21
c)5 (x-7)-2×=×-41
d)7 (×-9)-4×=×-39
e)4 (×+5)-3 (×-3)=2 (×+15)
f)5 (×+2)-4 (×-2)=3 (×+8)
g)2 [15+3 (×-1)]=4 (×+7)
h)2 [(4×-2)+16]=6 (×+5).
Coroana . Multumesc

Answer 1

a ) 5x + 3( x-6 ) = 7x + 13
5x + 3x - 18 = 7x + 13
8x - 18 = 7x + 13
8x - 7x = 13 + 18
x = 31
b ) 6x + 4( x-8 ) = 9x + 21 
6x + 4x - 32 = 9x + 21
10x - 32 = 9x + 21
10x - 9x = 21 + 32
x = 53
c ) 5( x-7 ) - 2x = x - 41
5x - 35 - 2x = x - 41
3x - 35 = x - 41
3x - x = -41 + 35
2x = -6
x = -3
d ) 7( x - 9 ) - 4x = x - 39
7x - 63 - 4x = x - 39
3x - 63 = x - 39
3x - x = - 39 + 63 
2x = 24
x = 12
e ) 4( x+5 ) - 3( x - 3 ) = 2( x + 15 )
4x + 20 - 3x - 9 = 2x + 30
x + 11 = 2x + 30
0 = 2x - x + 30 - 11
x + 9 = 0 
x = 0 - 9
x = -9
f ) 5( x + 2 ) - 4( x - 2 ) = 3( x + 8 )
5x + 10 - 4x - 8 = 3x + 24
x + 2 = 3x + 24
0 = 3x - x + 24 - 2
2x + 22 = 0
2( x + 11 ) = 0
x + 11 = 0
x = -11
g ) 2[ 15 + 3( x - 1 )] = 4( x + 7 )
2( 15 + 3x - 3 ) = 4x + 28
2( 12 + 3x ) = 4x + 28
24 + 6x = 4x + 28
6x - 4x = 28 - 24
2x = 4
x = 4:2
x = 2
h ) 2[( 4x - 2 ) + 16 ] = 6( x + 5 )
2( 4x - 2 + 16 ) = 6x + 30
2( 4x + 14 ) = 6x + 30
8x + 28 = 6x + 30
8x - 6x = 30 + 28
2x = 2
x = 2:2
x = 1

Answer 2

$a).5x+3(x-6)=7x+13 \\ 5x+3x-18=7x+13 \\ 5x+3x-7x=13+18 \\ x=31 \\ b).6x+4(x-8)=9x+21 \\ 6x+4x-32=9x+21 \\ 6x+4x-9x=21+32 \\ x=53$
$c).5(x-7)-2x=x-41 \\ 5x-35-2x=x-41 \\ 5x-2x-x=-41+35 \\ 2x=-6 \\ x=- \frac{6}{2} \\ x=-3 \\ d).7(x-9)-4x=x-39 \\ 7x-63-4x=x-39 \\ 7x-4x-x=-39+63 \\ 2x=24 \\ x= \frac{24}{2} \\ x=12$
$e).4(x+5)-3(x-3)=2(x+15) \\ 4x+20-3x+9=2x+30 \\ 4x-3x-2x=30-20-9 \\ -x=1 \\ x=-1 \\ f).5(x+2)-4(x-2)=3(x+8) \\ 5x+10-4x+8=3x+24 \\ 5x-4x-3x=24-10-8 \\ -2x=6 \\ x=- \frac{6}{2} \\ x=-3$
$g).2 [15+3 (x-1)]=4 (x+7) \\ 2(15+3x-3)=4x+28 \\ 2(12+3x)=4x+28 \\ 24+6x=4x+28 \\ 6x-4x=28-24 \\ 2x=4 \\ x= \frac{4}{2} \\ x=2$
$h).2 [(4x-2)+16]=6 (x+5) \\ 2(4x-2+16)=6x+30 \\ 2(4x+14)=6x+30 \\ 8x+28=6x+30 \\ 8x-6x=30-28 \\ 2x=2 \\ x= \frac{2}{2} \\ x=1$