Answer:
x²-8x-1=0
comparing above equation with ax²+bx+c=0
a=1
b=-8
c=-1
x=
=(--8+-√(64-4×1×-1)/2×1
=8+-√(64+4)/2
taking positive
x=(8+√68)/2=2(4+√17)/2=4+√17
taking negative
x=(8-√68)/2=2(4-√17)/2=4-√17
C. First person -hellobrains
Factorize x²+7x+12 ===> (x+3)(x+4)
Factorize x²-3x-28 ===> (x-7)(x+4)
4x + 12 can be written====> 4(x+3)
Then the question could be written as follows:
[(x+3)(x+4) / (x-7)(x+4) ] / 4(x+3) = [(x+3)(x+4) / (x-7)(x+4) ].[4(x+30]
After simplification you get 1 / 4(x-7)
Answer:
answer is 3
there are two ways to solve it. I hope you understand.
Answer:
3 dimes and 10 quarters
Step-by-step explanation:
If you add 7 dimes, then the number of dimes and quarters is the same, and the total increases to $3.50. A dime and a quarter have a value together of $0.35. Since there are equal numbers, the value $3.50 must be made up of some quantity of groups with a value of $0.35. That number of groups must be ...
... $3.50/$0.35 = 10
Thus, there are 10 quarters and 10-7 = 3 dimes.
_____
<em>Using an equation</em>
Let q represent the number of quarters. Then the amount Bess has is ...
... 0.10(q -7) +0.25q = 2.80
... 0.35q - 0.70 = 2.80
... 0.35q = 3.50 . . . . . add 0.70 . . . . . . . this should look familiar
... q = 3.50/0.35 = 10
