Question

37)The roots of the equation 7x² + x -1 = 0 are​

Answer 1

Step-by-step explanation:

0.3132 is the root of above equation

Answer 2

by the method,

-b±√(b²-4ac)/2a = x,

-1±√(1-4(7)(-1)/2(7) = (-1±√28)/14

= (-1±2√7)/14

thus, -(2√7-1)/14 and -(1+2√7)/14 are the roots of this equation...

[the formula]

7x² + x -1= 0

x² +x/7 = 1/7

x² + 2(x)(1/14) + (1/14)² = 1/7 + 1/(14)²{adding 1/14² on both sides}

[x+ 1/14]² = 29/196

:. x+ 1/14 = ±√29/14

x = (-1±√29)/14

that is,

0.3132 or -0.456 (approx)