Multiply the second equation by 2 so that its
6x+4y=-30
then subtract
6x+y=-39
6x+4y=-30
= -3y=-69
divide by -3 to isolate the y
then you get y=23
substitute the y value back into one of the equations to solve for x.
6x+23=-31
solve like you always do and you'll get your x
Congratulations, you solved a problem.
We need to solve for x by completing the square of the given mathematical expression (x+7)(x-9) = 25.
First, we need to perform multiplication of (x+7) and (x-9) such as the expression become:
(x+7) (x-9) = 25
x² -9x +7x -63 = 25
x² - 2x = 25 + 63
Then perform addition of constant values 25 and 63
x² - 2x =88
Add +1 in both sides to complete the expression such as:
x² - 2x +1 = 88 +1
(x-1)(x-1) = 89
(x-1)² = 89
We see that (x-1) is a perfect square, we can now solve for the value of x such as:
(x-1) = +-√89
x1 = +√89 + 1
x1 = 10.4
x2 = -√89 +1
x2 = -8.4
The answers are 10.4 and -8.4.
Answer:
B, 
Step-by-step explanation:
Using the law of cosines, which is 
, you can simply insert all the values.
c=|u+v|
a= r value of u (10)
b= r value of v (5)
To find C, you simply have to subtract v from u, and then subtract that number from 180 to find the reference angle.
I.E.: ∠135 - ∠30 = ∠105 ↔ 180 - 105 = 75 = C
so, the completed equation would be 10^{2} + 5^{2}- 2(10)(5)cos(75)
Answer:
......
Step-by-step explanation:
Length of diagonal of the rectangle=
√( length) ²+( breadth) ²
=√(20) ²+(12) ²
=√400+144
√544 m
. '. Length of fence= √544 m
Perimeter of the triangle formed by the diagonal of the rectangle =(12+20+√544)
=(32+√544) m
