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
Answer: 411.6
Step-by-step explanation: What is 411.6 Million in Scientific Notation?
To answer the question what is 411.6 million in scientific notation let’s recall how to convert 411,600,000 to scientific notation as detailed on our home page.
If you split the number 411600000 into a coefficient and a power of 10 you do get 411.6 million in exponential form, but there is an indefinite number of possibilities.
As you probably want 411.6 million in normalized scientific notation, the coefficient or significand of 411.6m in scientific notation must be in the interval [1,10[.
As there are many ways to express 411.6 million in scientific notation, in this post we mean 411.6 million in normalized scientific notation, unless stated otherwise.
Answer by answer key by key question equals equation
Answer:
Step-by-step explanation:
hello :
sin x + 2 sin x cosx = 0 equivalent to : sinx(1+2cosx) =0
sinx=0 means : general solution is : x= kπ....k in Z
1+2cosx=0 means : cosx= -1/2 general solution is : x= ±π/6+kπ...k in Z
