Use a let statement write an equation and check your solution.
(this is my algebra homework)
the difference between the square of a number and the number is 6. What is the number?
2014-12-04 1:13 am
回答 (6)
2014-12-04 1:18 am
Let the number = x
Then sqaure of the number = x²
Difference between them...
x² - x = 6
x² - x - 6 = 0
x² - 3x + 2x - 6 = 0
x(x - 3) + 2( x - 3) = 0
(x - 3)( x + 2) = 0
x - 3 = 0 then x = 3
x + 2 = 0 then x = -2
Check !!
(3)² - 3 = 9 - 3 = 6
(-2)² - (-2) = 4 + 2 = 6
Then sqaure of the number = x²
Difference between them...
x² - x = 6
x² - x - 6 = 0
x² - 3x + 2x - 6 = 0
x(x - 3) + 2( x - 3) = 0
(x - 3)( x + 2) = 0
x - 3 = 0 then x = 3
x + 2 = 0 then x = -2
Check !!
(3)² - 3 = 9 - 3 = 6
(-2)² - (-2) = 4 + 2 = 6
2014-12-04 1:17 am
let x = a number
then, x^2 = the square of a number
x^2 - x = 6
solve the quadratic equation: x^2 - x - 6 = 0
factor: (x - 3)(x + 2) = 0
solve: x = 3 or x = - 2
check:
when x = 3,
(3)^2 - 3 = 6
when x = - 2
(- 2)^2 - (- 2) = 4 + 2 = 6
qed
then, x^2 = the square of a number
x^2 - x = 6
solve the quadratic equation: x^2 - x - 6 = 0
factor: (x - 3)(x + 2) = 0
solve: x = 3 or x = - 2
check:
when x = 3,
(3)^2 - 3 = 6
when x = - 2
(- 2)^2 - (- 2) = 4 + 2 = 6
qed
2014-12-04 4:35 am
y= number y²-y=6 y²-y-6=0 (y-3)(y+2)=0 Thus, y= 3, -2 <= answers
Check: (3)²-3=6 or (-2)²-(-2)=6
Check: (3)²-3=6 or (-2)²-(-2)=6
2014-12-04 1:36 am
Thank you guys so much. Im not very good at word problems but with your help, i now understand. Thank you so much!!!!
2014-12-04 1:32 am
The difference between the square of a number and the number is 6. What is the number?
n^2 - n - 6 = 0
(n - 3)(n + 2) = 0
Solutions:
n = -2
n = 3
The number is -2 or 3.
n^2 - n - 6 = 0
(n - 3)(n + 2) = 0
Solutions:
n = -2
n = 3
The number is -2 or 3.
2014-12-04 1:25 am
x² – x = 6
x² – x – 6 = 0
(x + 2)(x – 3) = 0
x + 2 = 0 or x – 3 = 0
x = –2 or x = 3
x² – x – 6 = 0
(x + 2)(x – 3) = 0
x + 2 = 0 or x – 3 = 0
x = –2 or x = 3
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