Answer:
Step-by-step explanation:
a) -3
b) 5
c) -2
d) -6
Answer:
11x + 12
Step-by-step explanation:
( 4x + 12 ) + 7x
Remove parentheses.
= 4x + 12 + 7x
Group like terms.
= 4x + 7x + 12
Add similar elements: 4x + 7x = 11x
= 11x + 12
Answer:
27.5 minutes
Step-by-step explanation:
Using,
R/R' = 2ᵃ/ᵇ------------------ Equation 1
From the equation,
R = mass of Element X before radioactive decay, R' = mass of element X after radioactive decay, a = Time taken, b = half life.
Given: R = 870 grams, R' = 154 grams, b = 11 minutes.
Substitute these values into equation 1
870/154 = 2ᵃ/¹¹
(870/154)¹¹ = 2ᵃ
Solve for a
2ᵃ = (5.649)¹¹
2ᵃ = 187061.26
Taking the logarithm of both side,
Log2ᵃ = Log(187061.26)
⇒ a = log(187061.26)/log2
a = 8.272/0.301
a = 27.5 minutes
50% is

We have two ways to do this, pick your favor:
either by fractions:

÷

(

Multiply by the reciprocal of

which is 2(flip it)

× 2 =
= 1.25
Or change them to decimals:


= 0.5
0.625 ÷ 0.5
0.5 I 0.625
multiply by 10 to make it easier to divide(it still gives us the same answer)
0.5 × 10 = 5
0.625 × 10 = 6.25
1.25
5 I 6.25
-5
12
-10
25
-25
0
0.625 ÷ 0.5 =
1.25