Fill in the blank so that 81x2+_
x+81 is a perfect square trinomial.
81x²+

x+81

the blank is 162

since 81 and 81 are both perfect squares the middle term (blank) will be the product of their roots times 2

√81=9

√81 =9

9 x 9 x 2

= 162

b.an increase in a causes b to decrease

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5