SOLUTION: Could someone please solve this with the steps so I can see how its done? Solve the Equation 10y^2+y-2=0

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Could someone please solve this with the steps so I can see how its done? Solve the Equation 10y^2+y-2=0      Log On


   

Question 350043: Could someone please solve this with the steps so I can see how its done?
Solve the Equation
10y^2+y-2=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

10y%5E2%2By-2=0 Start with the given equation.


Notice that the quadratic 10y%5E2%2By-2 is in the form of Ay%5E2%2BBy%2BC where A=10, B=1, and C=-2


Let's use the quadratic formula to solve for "y":


y+=+%28-B+%2B-+sqrt%28+B%5E2-4AC+%29%29%2F%282A%29 Start with the quadratic formula


y+=+%28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%2810%29%28-2%29+%29%29%2F%282%2810%29%29 Plug in A=10, B=1, and C=-2


y+=+%28-1+%2B-+sqrt%28+1-4%2810%29%28-2%29+%29%29%2F%282%2810%29%29 Square 1 to get 1.


y+=+%28-1+%2B-+sqrt%28+1--80+%29%29%2F%282%2810%29%29 Multiply 4%2810%29%28-2%29 to get -80


y+=+%28-1+%2B-+sqrt%28+1%2B80+%29%29%2F%282%2810%29%29 Rewrite sqrt%281--80%29 as sqrt%281%2B80%29


y+=+%28-1+%2B-+sqrt%28+81+%29%29%2F%282%2810%29%29 Add 1 to 80 to get 81


y+=+%28-1+%2B-+sqrt%28+81+%29%29%2F%2820%29 Multiply 2 and 10 to get 20.


y+=+%28-1+%2B-+9%29%2F%2820%29 Take the square root of 81 to get 9.


y+=+%28-1+%2B+9%29%2F%2820%29 or y+=+%28-1+-+9%29%2F%2820%29 Break up the expression.


y+=+%288%29%2F%2820%29 or y+=++%28-10%29%2F%2820%29 Combine like terms.


y+=+2%2F5 or y+=+-1%2F2 Simplify.


So the solutions are y+=+2%2F5 or y+=+-1%2F2

If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim