need help with a couple of algebra problems

The plus signs are gone...don't put spaces around them and it will be ok.

y^2+8y = 0
y(y+8) = 0
y = 0 or y = -8

x^2+3x = 28
x^2+3x-28=0
(x+7)(x-4)=0
x = -7 or x = 4

2x^2+9x - 5 = 0
(2x-1)(x+ 5) = 0
x=1/2 or x=-5

Hope that helps!

1)
y^2 + 8y = 0
y(y + 8) = 0

y = 0

y + 8 = 0
y = -8

∴ y = -8 , 0

= = = = = = = =

2)
x^2 + 3x = 28
x^2 + 3x - 28 = 0
x^2 + 7x - 4x - 28 = 0
(x^2 + 7x) - (4x + 28) = 0
x(x + 7) - 4(x + 7) = 0
(x + 7)(x - 4) = 0

x + 7 = 0
x = -7

x - 4 = 0
x = 4

∴ x = -7 , 4

= = = = = = = =

3)
2x^2 + 9x - 5 = 0
2x^2 + 10x - x - 5 = 0
(2x^2 + 10x) - (x + 5) = 0
2x(x + 5) - 1(x + 5) = 0
(x + 5)(2x - 1) = 0

x + 5 = 0
x = -5

2x - 1 = 0
2x = 1
x = 1/2 (0.5)

∴ x = -5 , 1/2 (0.5)

New bug in Yahoo, it doesn't reproduce plus signs in questions.

Suggest you rewrite with word "plus" instead.


.