Answer:
Option 1,3 and 4 are correct.
Step-by-step explanation:
Given is a quadratic equation
[tex]x^2-10x+25=0[/tex]
Marcus used quadratic formula to solve this
The correct use of formula is
[tex]\frac{-b+/\sqrt{b^2-4ac} }{2a}[/tex]
for the quadratic equation [tex]ax^2+bx+c=0[/tex]
Comparing we have a =1, b =-10: c=25
The student should have substituted -10 for b but he wrong did only 10
II option is wrong since 2 is substituted correctly
III option is right -4ac i.e. the product x 4 must have been subtracted
IV option is right since repeated root is there so only one solution
