These questions are pertaining to College Algebra

Question

a) -4x^2= -9x+7

 

b) 0.2x^2-1.2x-0.2=0

Answer 1

a)  Get all terms on one side, 0 on other side, then either factor the equation, if possible, or use quadratic formula.

 

b) Answered already when you submitted this in an earlier posting.  (Please don't double-post)

Answer 2

a)  -4x²= -9x+7

 

Add 4x² to both sides

 

4x² - 9x + 7 = 0

For quadratic formula a=4, b=-9, c=7

 

x = [9±√[(-9)²-4(4)(7)]]/2(4)

 

x = [9±√(81-112)]/8

 

x = [9±√(-31)]/8

 

x = [9 ± i√31]/8

 

b) 0.2x^2-1.2x-0.2=0

 

First, get rid of the decimals by multiplying through by 5.

This changes the equation to  x²-6x-1=0

 

Then use the quadratic formula with a=1, b=-6, c=-1