Answer:
Step-by-step explanation:
hello :
the system is : x+ y =4 ...(*)
2x - y = -1...(**)
add(*) and (**) : 3x=3 so : x=1
put this value into (*) : 1+y=4 so : y=3
one solution : (1 , 3)
The correct answer is D The last one
Step by step is below
Hopefully this help you
Have a great day :)
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:
Length = 80 m and breadth = 60 m If one moves along the two adjacent sides, one covers 80+60 = 140 m. Diagonal of the rectangle = √ ( length^2 + breadth^2) ...
