There are 5 solutions for this system.
x^2 + 4y^2 = 100 ____1
4y - x^2 = -20 ____2
Add both 1 & 2 together. x^2 gets cancelled
4y^2 + 4y = 80 (send 80 to the other side and divide by 4)
Then equation the becomes : y^2 + y -20 =0
Now factorise the equation: (y+5) (y-4) = 0
Solve for y : y = -5 and y = 4
Using the values of y to find the values of x. From equation 1:
x^2 = 100 - 4y^2 x = /100 - 4y^2 (/ means square root) Replace values of y
y = -5, x = /100 - 4(-5)^2 = /100 - 100 = 0
y = 4, x = /100 - 4(4)^2 = / 100 - 64 = /36 = -6 or 6
Thus we have 6 solutions y = -5, 4 and x = -6, 0, 6
In both cases,
(as a consequence of the interesecting secant-tangent theorem)
So we have
10.
(omit the negative solution because that would make at least one of AB or AD have negative length)
11.
(again, omit the solutions that would give a negative length for either AB or AD)
Answer:
D. $1,136.79
Step-by-step explanation:
In this example, we want to learn what the original price of the computer would be if the price is $1,205, and this includes a 6% sales tax. This means that this price is 106% of the original price (100% is the price, while 6% is the tax). Therefore:
1205 * 1.06 = 1136.79
Step-by-step explanation:
I guess, it means every meter costs these amounts.
and the specified costs are not fit the whole bundle.
it is also unclear, if "half of it" means half of the original x meters, or half of the remaining meters (after selling 2/5 of the original meters). I assume the first.
so, we have
-5x
+ 2/5x × 5.5
+ 1/2x × 6.4
+ (10/10 - 4/10 - 5/10)x × 6 = + 1/10x × 6
= 120 ( a income minus costs is the profit, so balancing both sides in a "+" and "-" expression gives us the remaining profit).
about the line with the 1/10 :
the leftovers. 10/10 is the whole x at the beginning.
2/5 = 4/10.
1/2 = 5/10.
I brought all involved fractions to the same denominator of the smallest common multiple of 2 and 5 (10).
in full
-5x + (2/5)x×5.5 + (1/2)x×6.4 + (1/10)x×6 = 120
-5x + 2.2x + 3.2x + 0.6x = 120
-5x + 6x = 120
x = 120
so, he bought 120m in the first place.
Answer:
six
Step-by-step explanation:
6
