What should be added to twice the rational number -7/3 to get 3/7​

b = 5/7

Step-by-step explanation:

b is a rational number then

2b + (-7/3l =3/7

2b = 3/7+7/3

2b = (9 + 21)/21

2b =30/21

b = 30/42

therefore

b =5/7

answer: i can’t tell you that

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15