1ª) Resolva as equações abaixo:
a) (3x -2)/4 – (2x – 1)/5 – 1 = (7x – 3)/10
b) (4x -3)/5 – (2x + 7)/3 = 2x + 4
c) ( 23 x 3² - 6² ) : [ 18 : ( 15 – 3 x 2² )]²
d) 60 ÷ {2 · [-7 + 18 ÷ (-3 + 12)]} – [7 · (-3) – 18 ÷ (-2) + 1] =
e) (+4/9 ) – (-1/6 ) + (+1/2 ) – (+2/3 )
f) {[-6] - [(-2) . (-4) . (-1)] ÷ (-8)}
g) ( -3/8 ) – ( +2/5 ) ÷ (-1/2 )
a) (3x -2)/4 – (2x – 1)/5 – 1 = (7x – 3)/10
b) (4x -3)/5 – (2x + 7)/3 = 2x + 4
c) ( 23 x 3² - 6² ) : [ 18 : ( 15 – 3 x 2² )]²
d) 60 ÷ {2 · [-7 + 18 ÷ (-3 + 12)]} – [7 · (-3) – 18 ÷ (-2) + 1] =
e) (+4/9 ) – (-1/6 ) + (+1/2 ) – (+2/3 )
f) {[-6] - [(-2) . (-4) . (-1)] ÷ (-8)}
g) ( -3/8 ) – ( +2/5 ) ÷ (-1/2 )
Lista de comentários
20x3x-2/4- 20x2x-1/5-20=20x7x-3/10
5(3x-2)-4(2x-1)-20=2(7x-3)
15x-10-8x+4-20=14x-6
7x-26=14x-6
7x-14x=-6+26
-7x=20
-7x/(-7)=20/(-7)
x=-20/7
b) (4x -3)/5 – (2x + 7)/3 = 2x + 4
15x4x-3/5-15x2x+7/3=15x2x-15x4
3(4x-3)-5(2x+7)=30x+60
12x-9-10x-35=30x+60
2x-44=30x+60
2x-30x=60+44
-28x=104
-28x/(-28)=104/(-28)
x=104/(-28)
x=-104/28
c) ( 23 x 3² - 6² ) : [ 18 : ( 15 – 3 x 2² )]² ( '':'' ) não?
d) 60 ÷ {2 · [-7 + 18 ÷ (-3 + 12)]} – [7 · (-3) – 18 ÷ (-2) + 1]
60/(2(7-18+9))-(-20-+9+1)
60/(2x(-2))-(-11)
60/(-4)+11
-(60/4)+11
-15+11
-(15-11)
x= -4
e) (+4/9 ) – (-1/6 ) + (+1/2 ) – (+2/3 )
4/9-(-1/6)+0,5-2/3
4/9+1/6+1/2-2/3
8+3+9+12/18
8/18
x= 4/9
f) {[-6] - [(-2) . (-4) . (-1)] ÷ (-8)}
-6-(-8)/(-8)
-6-1-(6+1)
x= -7
g) ( -3/8 ) – ( +2/5 ) ÷ (-1/2 )
(-0,375)-0,4+(-0,5)
-0,375-2/5/(-1/2)
-3/8+2/5/x2
-3/8+2/1
-3/8+2x2/5x1
-3/8+4/5
-15+32/40
x= 17/40