Let x = your number.
x^2 - 21 = 4x. Subtract 4x from both sides.
x^2 - 4x - 21 = 0. Factor.
(x - 7) (x + 3) = 0. Set each term to 0.
x + 3 = 0. Subtract 3 from both sides.
x = -3. This is the negative solution.
Set the other term equal to zero.
x - 7 = 0. Add 7 to each side.
x = 7. This is the positive solution.
BC = EF
the side has to lie between the two angles
Answer:
8x2=16 9x7=63
63+16=79
Step-by-step explanation:
The answer is on the photo below, I hope I helped! Hope you do well!!!
Answer: hours
Step-by-step explanation:
Let x be the time ( in hours ) you feel good and y be the time ( in hours ) that you get tired.
As per given , we have
x+y= 8
Since :
So , we have
20x+12y=122
According to the given question , we have the following system of equations ,
Multiply 12 on both sides of equation (1) , we get
Eliminate equation (3) from (2) , we get
Hence, you felt hours good.