Answer:
x=2.87083
Explanation:
y = –2x^2 + 4x +5
ax^2 + bx + c = 0
a= -2
b= 4
c= 5
Quadratic formula: x= -b±√b^2-4ac over 2a
1. plug in the numbers
2. x= -4 ± √4^2 -4(-2)(5) over 2(-2)
3. x= -4 ± √16+40 over -4
4. x= -4 ± √56 over -4
next simplify ratidal
x= -4 ± √2·2·2·7 over -4
x= -4 ± 2√2·7 over -4
x= -4 ± 2√14 over -4
divide both sives over four
x= -4 over -4 ± 2√14 over -4
x= -1 over -1 ± √14 over -2
answer:
x=2.87083