84-2r-2r² factorisation
Answers
Answered by
1
84 - 2r - 2r^2 =. - 2r^2 - 2r + 84
= 2r^2 + 2r - 84
2r^2 + 2r -84
a = 2 , b = 2 , c = -84
By quadrilateral equation
x =. - 2 +/- √[ 2^2 - (4 × 2× (-84))] / (2×2)
=. -2 +/- √[4 + 672] / 4
=. - 2+/- 26 / 4
===> -2 + 26 / 4. =====> -2 - 26 / 4
= 24 / 4. =. -28 / 4
= 6. = -7
Similar questions