Question

Me ajudem achar o valor de x Nessas operaçoes ,

a)3(x+2) = 15 =) 3 x + 6 = 15

b) 5 (x-1) =30

c)2(x-1)-7=16

d)7 (x2) = 5 (x +3 )

e) 2 ( x -5) - x = 10 - 3 x

f) 2 (x-5) + 4 ( x - 1 = 0

Answer 1

a)

3x+6=15--> 3x=15-6-->3x=9 --> x=3

b)

5(x-1)=30 --> 5x-5=30 --> 5x=30+5 --> 5x=35 --> x=7

c)

2(x-1)-7=16 --> 2x-2-7=16 --> 2x=16+2+7 --> 2x=25 --> x=25/2=12,5

d)

7x^2=5x+15 --> 7x2-5x-15=0--> x=5+-(raiz de) 25- 4(7)(-15)  / 2*7

--> x=5 +- 21/14 --> x= 26/14 =13/7   OU   x= -16/14 = -8/7

e)

2(x-5) - x=10-3x --> 2x-10-x =10-3x --> 2x-x+3x = 10+10--> 4x=20--> x=5

f)

2x+10+4x-4=0 --> 2x+4x=-10+4 --> 6x=-6 --> x= -6

Answer 2

a) )3(x+2) = 15

3 x + 6 = 15

3x= 15 - 6

x= 9/3

x= 3

b)  5 (x-1) =30

5x - 5 = 30

5x = 30 + 5

x =  35/5

x= 7

c) 2(x-1)-7=16

2x - 2 - 7 =16

2x = 16 + 9

x= 25/2 = 12,5

d) 7 (x2) = 5 (x +3 )

14x = 5x + 15

14x - 5x = 15

9x = 15

x= 15/9 = 1,6

e) 2 ( x -5) - x = 10 - 3x

2x -10 -x = 10 - 3x

x + 3x  = 10 + 10

4x = 20

x= 20/4

x= 5

f)  2 (x-5) + 4 (x - 1) = 0

2x - 10 + 4x - 4 = 0

6x - 14 = 0

6x= 14

x= 14/6

x= 2,33