X^2-6x+7=0
-b +/- sqrt b^2-4ac all over 2a
a=1 b= -6 and c=7
6+/- sqrt 36-4×1×7 all over 2×1
6+/- sqrt 8 all over 2
6+/- 2sqrt2 all over 2
reduce
3+/- sqrrt2
11*57+X(1+2+3+.....+56)
=11*57+X(1+56)*56/2
=627+1596X
=19779
X=(19779-627)/1596=12
Your answer is C
Answer:
-24n + 42
Step-by-step explanation:
(7 - 4n) · 6
Apply distribute property.
7 · 6 - 4n · 6
42 - 24n
