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I need help please
whats the anwser

I need help please whats the anwser-example-1
User Sebin
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1 Answer

25 votes
25 votes

Answer:

  • x = -0.90, y = 2.31
  • x = 1.40, y = 9.19

Explanation:

Equating the expressions for y will give a quadratic in x:

4x^2 +x = 3x +5

4x^2 -2x = 5 . . . . . . collect x-terms on the left

4(x^2 -1/2x) = 5 . . . .factor out the leading coefficient

4(x^2 -1/2x +1/16) = 5 4/16 . . . . complete the square

4(x -1/4)^2 = 84/16 . . . . write the quadratic as a square

x -1/4 = (±√21)/4 . . . . . divide by 4 and take the square root

x = (1 ±√21)/4 . . . . . . . add 1/4

y = 3x +5 = 3(1 ±√21)/4 +5 = (23 ±3√21)/4 . . . . use the linear equation for y

The solutions are ...

x = (1 -√21)/4; y = (23 -3√21)/4 ≈ 2.31

x ≈ -0.89, y ≈ 2.31

x = (1 +√21)/4; y = (23 +3√21)/4

x ≈ 1.40, y ≈ 9.19

I need help please whats the anwser-example-1
User Wajdi Hh
by
3.3k points