Hello from MrBillDoesMath!
Answer:
x = 10
Discussion:
A plane triangle contains 180 degrees. Adding the angles in the triangle shown in #8 gives
(4x + 7) + (3x + 13) + 90 = 180
Note the "right angle" shown in the triangle has been replaced by its 90 degree equivalent in the above equation.
Combining like terms gives
( 4x + 3x) + (7 + 13) + 90 = 180
7x + 20 + 90 = 180 => (subtract 90 from each side)
7x + 20 + 90 - 90 = 180 - 90 = 90 =>
7x +20 = 90 => (subtract 20 from each side)
7x + 20 -20 = 90 -20 =>
7x = 70 =>
x 70/7 =10.
Thank you,
MrB
Hello :
the consecutive room numbers are : n , n+1
n(n+1) =420
n²+n -420 = 0
the discriminant delta = b² - 4ac ( a = 1 and b = 1 and c = - 420
delta = (1)²-4(1)(-420) =1681= 41²
n = (-1 -41)/2 ( refused negatif number)
or
n = (-1+41)/2 =20
<span> the room numbers.are : 20 , 21</span>
Answer:
Step-by-step explanation:
1) Factor out the x components of the equation
(x+3)(x+1)=0
2) Take each individual term and find the value for which the equation equals zero:
x+3=0 -> x=-3
x+1=0 -> x=-1
x = -3, -1
