Answer:
5 is your answer for u.
Step-by-step explanation:
Note the equal sign, what you do to one side of the equation, you do to the other.
First, multiply 15 and 5 to both sides of the equation (to get rid of the denominators):
[tex]15 * 5 * (\frac{u + 7}{15}) = (\frac{4}{5}) * 5 * 15\\5 * (u + 7) = 4 * 15[/tex]
First, distribute the 5 to all terms within the parenthesis. Also, simplify the right side by multiplying:
[tex]5 * (u + 7) = 4 * 15\\(5 * u) + (5 * 7) = (4 * 15)\\5u + 35 = 60[/tex]
Next, isolate the variable, u. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
PEMDAS is the order of operations, and stands for:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
~
First, subtract 35 from both sides, and then divide by 5 to isolate the variable, u:
[tex]5u + 35 = 60\\5u + 35 (-35) = 60 (-35)\\5u = 60 - 35\\5u = 25\\\\\\\frac{5u}{5} = \frac{25}{5} \\u = \frac{25}{5} = 5\\u = 5[/tex]
