+0  
 
0
99
4
avatar

I managed to get a start on the first one, but now I'm stuck. I have no clue how to do the other two. 

 

a. 

y - 3x = 2z^2 + 8

y - 3x = 2(5x-3)^2 + 8

y - 3x =  2(25x^2 - 30x + 9) + 8

y - 3x =  50x^2 - 60x + 26

50x^2 - 60x + 26 = y - 3x

50x^2 - 57x + 26 = y

?

 

b. ?

 

c. ?

 Jan 3, 2021
 #1
avatar+112816 
+1

I assume you are being asked to make x the subject.

 

I'll start half way through your working.

 

\(y - 3x = 50x^2 - 60x + 26\\ y = 50x^2 - 57x + 26\\ 2y-52 = 100x^2 - 114x \\ \frac{2y-52}{100} = x^2 - 1.14x \\ \text{Complete the square}\\ \frac{2y-52}{100} +(0.57)^2= x^2 - 1.14x+(0.57)^2 \\ \frac{2y-52}{100} +0.3249= (x-0.57)^2 \\ \frac{2y-52+32.49}{100} = (x-0.57)^2 \\ \frac{2y-19.51}{100} = (x-0.57)^2 \\ \pm\frac{\sqrt{2y-19.51}}{10} = (x-0.57) \\ x=0.57\pm\frac{\sqrt{2y-19.51}}{10} \\ x=\frac{5.7\pm\sqrt{2y-19.51}}{10} \\\)

You will need to check for careless mistakes.

 Jan 3, 2021
 #2
avatar+112816 
0

The second one is easy.  The last one is not so bad either.

 Jan 3, 2021

31 Online Users

avatar
avatar