Question

@rvc @kelliegirl33 how do i factor 3x^2-4x-7

Answer 1

@Michele_Laino

Answer 2

This video helped me @knightmare6 http://www.virtualnerd.com/algebra-1/polynomials-and-factoring/trinomial-factorization-example.php

Answer 3

hint:
the requested factorization, is given by the subsequent formula:
\[\Large 3\left( {x - {x_1}} \right)\left( {x - {x_2}} \right)\]
where x_1 and x_2 are the solution of this equation:
\[\Large 3{x^2} - 4x - 7 = 0\]

Answer 4

solutions*

Answer 5

okay so i need to find x

Answer 6

yes!

Answer 7

do i use the equation -b/2a?

Answer 8

you should get 2 solutions, namely you have to use this equation:
\[\Large x = \frac{{ - b \pm \sqrt {{b^2} - 4 \times a \times c} }}{{2 \times a}}\]

Answer 9

when multiplied= -21
when added = --4

Answer 10

im so confused

Answer 11

find two numbers such that when they are multiplied their product equals -21
and when they are added the sum equals -4

Answer 12

where did you get -21?

Answer 13

\[\large 3x^2-4x-7=0\]

multiply the co-efficient of \(\ x^2\) and the constant

Answer 14

well i do this way
if you follow this you will get
(x+ )(x+ )

Answer 15

okay so just go step by step im confused.

Answer 16

wait i got it is it (x+1)(3x-7)?

Answer 17

okay
so what will be the two numbers?
example
\[x^2+5x-6=0\]
here we need two numbers such that their sum is 5 and their product is -6
so the two numbers are 6 and -1
6 X -1 = -6
6 + (-1) = 5
so the next step would be
\[\large x^2-x+6x-6=0\]
\[\large x(x-1)+6(x-1)=0\]
\[\large (x-1)(x+6)=0\]