Answer:
b = -11
Step-by-step explanation:
4x² + bx + 7 = 0
a = 4 ; b = b ; c = 7
If the discriminant is greater than zero, then the quadratic equation will have a real solution.
D = b² - 4ac
= b² - 4 * 4 *7
= b² - 112
b² - 112 > 0
b² > 112
From the given options, b = -11 satisfies the above condition.
(-11)² > 112
121 > 112
Answer: b = -11
Option 1) b = 5, b² = 25
25 is less than 112.
Option2) b = 9; b² = 9² = 81
81 is less than 112.
Option 3) b = (-8) ; b² = (-8)² = 64
64 is less than 112.
