algebra factoring

Question

2x^2+15=-11x and 3x^2=-4x

Answer 1

2x^2 + 11 +15 = 0

(2x+5)(x+3) = 0

3x^2 = -4x

3x^2+4x = 0

x(3x+4) = 0

Answer 2

Hi,

2x^2+15=-11x

2x^2+15 + 11x = 0

2x^2+ 11x + 15 = 0

First, you see a ( coefficient of x^2 is not perfect square) so equation times 2 and also divided by 2

1/2 ( 4x^2 + 11x + 30) be careful I kept b as 11 ( no change)

1/2( 2x + 6 ) ( 2x + 5 ) in fact, you need to find two numbers that multiplication of them is 30 and add is 11

now think, 1/2 times which parenthesis works for you? first one. Good job

if you need to find the solutions: x + 3 = 0 -----> x = -3 and 2x + 5 = 0 x = - 5/2



( x + 3 ) ( 2x + 5 ) you can distribute and find the given expression

( x + 3 ) ( 2x + 5 ) = 2x^2 + 5x + 6x + 15 = 2x^2 + 11x + 15 ( for checking)

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3x^2=-4x ----> 3x ^2 + 4x = 0 factor of x -----> x( 3x + 4 ) = 0 -----> x = 0 and 3x + 4 = 0 ---> x = - 4/3

I hope it is useful,

Minoo