Perhaps the most concise way to factor is by "completing the square" which is how the quadratic formula is derived...
x^2+6x+8=0 move constant to other side, subtract 8 from both sides
x^2+6x=-8, halve the linear coefficient, square it, then add that to both sides, in this case (6/2)^2=3^2=9
x^2+6x+9=1 now the left side is a perfect square of the form
(x+3)^2=1 take the square root of both sides
x+3=±√1 subtract 3 from both sides
x=-3±√1
x=-3±1
x=-4 and -2
Since the zeros occur when x=-4 and -2 the factors of the equation are:
(x+2)(x+4)
Answer:
Step-by-step explanation:
0
r
= 1
Answer:
13, 18, 72
Step-by-step explanation:
let x-5 represent the first number, since the first number is 5 less than the third number. let x represent the third number. let 4x represent the third number, since it's four times greater than the third number.
set up an equation, and make it equal to 103:
x-5+x+4x=103
solve:
6x-5=103
6x=108
x=18
so, the third number is 18.
the first number is equal to x-5, so:
18-5=13
the second number is equal to 4x, so:
4(18)=72
so, the three numbers are 13, 18, and 72.
Answer:C- 3x - 7y and 3y - 7x
Step-by-step explanation:
