Question

Equação do primeiro grau :

a) 5x = -30
b) 7x = 22
c) 4x = -20
d) x+8 = 2x
e) 5 = 8 - x
f) 2x+7 = x
g) 3-x = 2
h) x-8 = 5
i) -3 = 2+x
j) 4 = x+2
k) x-6 = 3
l) x + 2 = 7

Obrigado.

Answer 1

A ) 5x = - 30
x = - 30/5
x = - 6

B ) 7x = 22
x = 22/7
x = 3,14

C ) 4x = - 20
x = - 20/4
x = - 5

D) x + 8 = 2x
x - 2x = - 8
- x = - 8 . ( - 1 )
x = 8

E ) 5 = 8 - x
x = 8 - 5
x = 3

F ) 2x + 7 = x
2x - x = - 7
x = - 7

G ) 3 - x = 2
- x = 2 - 3
- x = - 1 . ( - 1 )
x = 1

H )

H ) x - 8 = 5
x = 5 + 8
x = 13

I ) - 3 = 2 + x
- x = 2 + 3
- x = 5 . ( - 1 )
x = - 5

J ) 4 = x + 2
- x = 2 - 4
- x = - 2 . ( - 1 )
x = 2

K ) x - 6 = 3
x = 3 + 6
x = 9

L ) x + 2 = 7
x = 7 - 2
x = 5

Answer 2

a) $5x=30$

$x=\dfrac{30}{5}$

$\boxed{x=6}$


b) $7x=22$

$\boxed{x=\dfrac{22}{7}}$


c) $4x=-20$

$x=\dfrac{-20}{4}$

$\boxed{x=-5}$


d) $x+8=2x$

$2x-x=8$

$\boxed{x=8}$


e) $5=8-x$

$x=8-5$

$\boxed{x=3}$


f) $2x+7=x$

$2x-x=-7$

$\boxed{x=-7}$


g) $3-x=2$

$x=3-2$

$\boxed{x=1}$


h) $x-8=5$

$x=5+8$

$\boxed{x=13}$


i) $-3=2+x$

$x=-3-2$

$\boxed{x=-5}$


j) $4=x+2$

$x=4-2$

$\boxed{x=2}$


k) $x-6=3$

$x=3+6$

$\boxed{x=9}$


l) $x+2=7$

$x=7-2$

$\boxed{x=5}$