from the sum of 3x square -5x+2 and -5x square - 8x +6 subtract 4x square - 9x + 7
Answers
Simplifying
x2 + -8x = 9
Reorder the terms:
-8x + x2 = 9
Solving
-8x + x2 = 9
Solving for variable 'x'.
Reorder the terms:
-9 + -8x + x2 = 9 + -9
Combine like terms: 9 + -9 = 0
-9 + -8x + x2 = 0
Begin completing the square.
Move the constant term to the right:
Add '9' to each side of the equation.
-9 + -8x + 9 + x2 = 0 + 9
Reorder the terms:
-9 + 9 + -8x + x2 = 0 + 9
Combine like terms: -9 + 9 = 0
0 + -8x + x2 = 0 + 9
-8x + x2 = 0 + 9
Combine like terms: 0 + 9 = 9
-8x + x2 = 9
The x term is -8x. Take half its coefficient (-4).
Square it (16) and add it to both sides.
Add '16' to each side of the equation.
-8x + 16 + x2 = 9 + 16
Reorder the terms:
16 + -8x + x2 = 9 + 16
Combine like terms: 9 + 16 = 25
16 + -8x + x2 = 25
Factor a perfect square on the left side:
(x + -4)(x + -4) = 25
Calculate the square root of the right side: 5
Break this problem into two subproblems by setting
(x + -4) equal to 5 and -5.
Answer:
Step-by-step explanation:
4x^2-8x(k+1)-8=0
for some value of x
it's given that one root is negative of other
then
8(k+1)/4=0
k=-1
-x^2+3x+2=0
=>x=2or1(factorize)
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