Simplfy-2[9-(x+7)] answer this question

2x-4

Step-by-step explanation:

Apply the distributive property.

−

2

(

9

−

x

−

1

⋅

7

)

Multiply  

−

1

 by  

7

.

−

2

(

9

−

x

−

7

)

Simplify by multiplying through.

Subtract  

7

from  

9

.

−

2

(

−

x

+

2

)

Apply the distributive property.

−

2

(

−

x

)

−

2

⋅

2

Multiply  

−

1

by  

−

2

.

2

x

−

2

⋅

2

Multiply  

−

2

by  

2

.

2

x

−

4

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

answer: 457.14

step-by-step explanation:

205 - 45 = 160

160 / .35 = 457.142857