Sure, let's solve the equation step by step. We are given:
[tex]\[ 86 - u = 156 \][/tex]
1. Isolate \( u \) on one side of the equation:
First, let's get the terms involving \( u \) by themselves. To do this, we need to move the constant term (86) from the left side to the right side of the equation. We can do this by subtracting 86 from both sides:
[tex]\[ 86 - u - 86 = 156 - 86 \][/tex]
2. Simplify both sides of the equation:
On the left side of the equation, \( 86 - 86 \) becomes 0, so we have:
[tex]\[ -u = 70 \][/tex]
3. Solve for \( u \):
To solve for \( u \), we need to isolate \( u \) on one side of the equation. Since \( -u \) means \( -1 \times u \), we can divide both sides of the equation by \(-1\):
[tex]\[ u = \frac{70}{-1} \][/tex]
4. Simplify the expression:
Dividing by \(-1\) gives us:
[tex]\[ u = -70 \][/tex]
So, the value of \( u \) is:
[tex]\[ u = -70 \][/tex]