You use the Pitagora formula:
CD^2+BD^2= (6x-10)^2
CD^2+AD^2=16x^2
AD^2-BD^2=16x^2-(36x^2-120x+100)
0=-20x^2+120x-100
x^2-6x+5=0
x^2-x-5x+5=0
x(x-1)-5(x-1)=0
(x-1)(x-5)=0
x1=1 but if x=1 it means that BC=-4 which cannot be possible
x2=5 so x=5
The answer to your question is C. I hope that this is the answer that you were looking for and it has helped you.
Let x be the time it takes Elias and Niko to polish the silver working together. If Elias works alone, he could polish all the silver himself in 40 minutes. Then, in 1 minute, he will make 
of the total work. If the same analysis is applied Niko, in 1 minute, will make 
of the total work.
Working together Elias and Niko will need x minutes to make all the work. Then, in 1 minute, they will make 
of the total work. So, the fraction of the total work they make in 1 minute is given by this equation:
Answer:
y=3x+3
Step-by-step explanation:
y=mx+b is slope intercept form
to find the slope(m) you need to plug your numbers into the equation y(2)-y(1)/x(2)-x(1)
which means subtract the Y's together and the X's together and put the quotient of the Y's on top. Note that you have to choose a set of number to be the first group and the other set as the second group
so (0-6)/(-1-1) = -6/-2 = 3
3 will be your slope. plug that and a set of your numbers into the slope intercept equation
0=3(-1)+b
0=-3+b
3=b
y=3x+3
<h3>
Answer: x-2y = -8</h3>
===========================================
Explanation:
Multiply both sides by 2 to clear out the fraction
y = (1/2)x+4
2y = 2[ (1/2)x + 4 ]
2y = 2*(1/2)x + 2*4
2y = x + 8
Then move the x term over to the left side
2y = x+8
2y-x = 8
-x+2y = 8
Optionally we can multiply both sides by -1
-x+2y = 8
-1*(-x+2y) = -1*8
x-2y = -8
This is in standard form Ax+By = C with A = 1, B = -2, C = -8
The reason why I multiplied both sides by -1 was to make A > 0 which is what some textbooks use as convention. Of course -x+2y = 8 is equally valid too.
