Answer:
B
Step-by-step explanation:
x + 3y = 7 → (1)
3x + 2y = 0 → (2)
Multiplying (1) by - 3 and adding to (2) will eliminate x
- 3x - 9y = - 21 → (3)
Add (2) and (3) term by term to eliminate x
0 - 7y = - 21
- 7y = - 21 ( divide both sides by - 7 )
y = 3
Substitute y = 3 into either of the 2 equations and solve for x
Substituting into (1)
x + 3(3) = 7
x + 9 = 7 ( subtract 9 from both sides )
x = - 2
solution is (- 2, 3 ) → B
Answer:
d. The common ratio is 1.1
Step-by-step explanation:
To see if the data has a common ratio or common difference, we have to see if the division between them is equal(common ratio), or if the difference between them is equal(common difference).
In this case, since 
, it has a common ratio.
To find it, we divide consecutive terms. For example:
So the correct answer is:
d. The common ratio is 1.1
Step-by-step explanation:
A = A₀ ½^(t / T)
where A is the amount left, A₀ is the original amount, t is time, and T is the half life.
4 days is 96 hours, so the amount left is:
A = 600 ½^(96 / 15)
Answer: y > 4.5 or y < -4.5
You use the rule
if |y| > k, then y > k or y < -k
where k is some positive number. In this case, k = 4.5
Answer:
Step-by-step explanation:
<u>Jamie's working speed is:</u>
<u>And Bob's speed is</u>:
<u>Their working speed together is:</u>
<u>Solving for x:</u>
- 1/x = 1/30 - 1/75
- 1/x = 5/ 150 - 2/150
- 1/x = 3/150
- 1/x = 1/50
- x = 50
Bob can do the job in 50 minutes
