Answer:
a=29/42
Step-by-step explanation:
6a-1÷7=4
first write the division as a fraction
6a-1/7=4
add 1/7 to each side
6a=4+1/7
which is equal to
6a=29/7
divide both sides by 6
a=29/42
Answer:
(- 2, 6 )
Step-by-step explanation:
Given the equations
3x + 2y = 6 → (1)
y - x = 6 ( multiply through by 3 to clear the fraction )
2y - 3x = 18 ( add 3x to both sides )
2y = 18 + 3x → (2)
Substitute 2y = 18 + 3x into (1)
3x + 18 + 3x = 6
6x + 18 = 6 ( subtract 18 from both sides )
6x = - 12 ( divide both sides by 6 )
x = - 2
Substitute x = - 2 into (1) and solve for y
3(- 2) + 2y = 6
- 6 + 2y = 6 ( add 6 to both sides )
2y = 12 ( divide both sides by 2 )
y = 6
solution is (- 2, 6 )
It is b because it makes sense
Answer:
A. 2.8 billion years old
Step-by-step explanation:
1/16 = (1/2)^4, so 4 half-lives have elapsed.
4 · 0.700 billion years = 2.8 billion years
The rock is 2.8 billion years old.