The value of n needed to make the equation true.
n+19=40

n = 21

Step-by-step explanation:

Given

n + 19 = 40 ( subtract 19 from both sides )

n = 40 - 19 = 21

n = 21

Step-by-step explanation: When you're asked to solve for n in an equation, what your really being asked to do is to get x by itself on one side of the equation.

In this problem, since 19 is being added to n, in order to get n by itself, we must subtract 19 from the left side of the equation and when we subtract 19 from the left side of the equation, remember that we must also subtract 19 from the right side of the equation.

So on the left, +19 and -19 cancel eachother out and

on the right, 40 - 19 is 21 so n = 21.

We can check our answer by substituting

a 21 back into the original equation.

So we have (21) + 19 = 40 or 40 = 40.

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