Final answer:
To find a pair of integer values for a and c so that ax²+4x+c=0 has two imaginary solutions, set a = 1 and c = 1. The equation x²+4x+1=0 then has two imaginary solutions.
Step-by-step explanation:
To find a pair of integer values for a and c so that ax²+4x+c=0 has two imaginary solutions, we need the discriminant (b²-4ac) to be negative. Let's set a = 1 as an integer value. For imaginary solutions, the discriminant should be negative. So, we can set c = 1.
Now, the equation becomes x²+4x+1=0, which has two imaginary solutions.