Question

X² - 7x + 9 - 7 + 6 = 0

Answer 1

x²-7x+8=0
ax²+bx+c=0

a=1
b=-7
c=8

delta= b²-4●a●c

delta= -(7)² -4●(1)●(8)

delta= 49+32

delta= 81

x= -b +/-√delta
-----------------------
..........2●a

x= -(-7) +/- √81
----------------------
...........2●(1)

x=7+/-9
------------
...... 2

x'=7+ 9..... x"= 7- 9
----------- ^ -------------
2...................... 2

x'= 16.......... x"= -2
----------- ^ ------------
2....................... 2

x'=8 ^ x"=1