If x = 1 is a common root of ax² + ax + 2 = 0 and x² + x + b = 0, then ab =

ab = 2

Step-by-step explanation:

Given equations

ax² + ax + 2 = 0

x² + x + b = 0

root of both the equation

x = 1

then we can plug in x = 1 in both the equation

ax² + ax + 2 = 0 x² + x + b = 0

a*1² + a*1 + 2 = 0 1² + 1 + b = 0

a + a + 2 = 0 1 + 1 + b = 0

2a + 2 = 0 2 + b = 0

2a = - 2 b = - 2

a = - 2/2 = - 1

Thus,

a = - 1

b = - 2

a*b = - 1*-2 = 2

ab = 2