Answer:
x = -1 and y = 1/2
Step-by-step explanation:
Let u = 1/x, and v = 1/y
Then the pair of equations
-3/x + 4/y = 11
1/x - 2/y = -5
Can be written as
-3u + 4v = 11 .................................(1)
u - 2v = -5......................................(2)
From (2)
u = 2v - 5 .......................................(3)
Substituting (3) into (1)
-3(2v - 5) + 4v = 11
-6v + 15 + 4v = 11
-6v + 4v = 11 - 15
-2v = -4
v = 4/2 = 2
Substituting this value of v in (3)
u = 2v - 5
u = 2(2) - 5
= 4 - 5
= -1
That is
u = -1, v = 2
Since u = 1/x, and v = 1/y, we have
1/x = -1
=> x = -1
And
1/y = 2
=> y = 1/2
Therefore
x = -1 and y = 1/2
Answer:
In the Garden Club the cost will be a fixed fee of $25 and $10 for each rosebush, so if he buys X rosebushes, the total cost will be:
C1(X) = $25 + $10*X
While in the local nursery there is no initial cost, and each rosebush costs $15, so if he buys X rosebushes, the total cost will be:
C2(X) = $15*X
Now, let's find the value of X where C1 and C2 are equal, this is:
$25 + $10*X = $15*X
$25 = $15*X - $10*X = $5*X
X = 25/5 = 5
This means that if he buys 5 rosebushes, he will pay the same amount in both places.
If he buys less than 5 rosebushes, he will pay less in the local nursery (as it has a bigger slope, but no initial fee)
If he buys more than 5 rosebushes, he will pay less in the Garden club (because it has a smaller slope)
For sake of convenience, reverse the series, then it would be:
21,19,17.....7
a=21, d = -2,
s(4) = 4/2 (21+15)
s(4)=2(36)
s(4) = 72
Answer:
Step-by-step explanation:
OPQ is a right angle triangle.
<u>Using Pythagoras</u>
<u>Using quadratic formula</u>
<u />
OR
(Length can't be negative)
∴
E. II or IV only because it will have different signs if point Q was in either of those quadrants
