Solve the quadratics, use any method that works for you, show all your work a) y=3x2+9x+2 b) 8x2=−11x+4

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Solve the quadratics, use any method that works for you, show all your work  a) y=3x2+9x+2  b) 8x2=−11x+4

ol3i4c5s4hr · Accepted Answer

Step 1  a) y=3x2=9x+2  f(x)=3x2+9x+2  f(x)=0  3x2+0x+2=0  x=−9±92−4(3)(2)2(3)  x=−9±81−246  x=−9±576  ∴x=−9−576, −9+576  Step 2  b) 8x2=−11x+4  8x2+11x−4=0  x=−11±112−4(8)(−4)2(8)  x=−11±121+12816  x=−11±24916  ∴x=−11−24916, −11+24916

jean2098 · Accepted Answer

Step 1  Given: y=3x2+9x+2  Swap sides so that all variable terms are on the left hand side.  3x2+9x+2=y  Subtract y from both sides.  3x2=9x+2−y=0  This equation is in standard form: ax2+bx+c=0. Substitute 3 for a, 9 for b, and 2−y for c in the quadratic formula, −b±b2−4ac2a  x=−9±92−4×3(2−y)2×3  Square 9.  x=−9±81−4×3(2−y)2×3  Multiply -4 times 3.  x=−9±81=12(2−y)2×3  Multiply -12 times 2-y  x=−9±81+12y−242×3  Add 81 to −24+12y  x=−9±12y+572×3  Multiply 2 times 3  x=−9±12y+576  Now solve the equation x=−9±12y+576 when ± is plus. Add -9 to 57+12y  x=12y+57−96  Divide −9+57+12y by 6  x=12y+576−32  is minus  x=−12y+57−96  Divide −9−57+12y by 6  x=−12y+576−32  Step 2  b) 8x2=−11x+4  Add 11x to both sides.  8x2+11x=4  Subtract 4 from both sides  8x2+11x−4=0  x=−11±112−4×8(−4)2×8  Square 11.  x=−11±121−4×8(−4)2×8  Multiply -4 times 8

Solve the quadratics, use any method that works for you,

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