Algebra<span><span>Introduction to Algebra
</span>Variables<span>
</span>Expressions<span>
</span>Equations<span>
</span>Solution of an equation<span>
</span>Simplifying equations<span>
</span>Combining like terms<span>
</span>Simplifying with addition and subtraction<span>
</span>Simplifying by multiplication<span>
</span>Simplifying by division<span>
</span>Word problems as equations<span>
</span>Sequences VariablesA variable is a symbol that represents a number. Usually we use letters such as n, t, or x for variables. For example, we might say that s stands for the side-length of a square. We now treat s as if it were a number we could use. The perimeter of the square is given by 4 × s. The area of the square is given by s× s. When working with variables, it can be helpful to use a letter that will remind you of what the variable stands for: let n be the number of people in a movie theater; let t be the time it takes to travel somewhere; let d be the distance from my house to the park. ExpressionsAn expression is a mathematical statement that may use numbers, variables, or both.Example:The following are examples of expressions:2x3 + 72 × y + 52 + 6 × (4 - 2)z + 3 × (8 - z<span>)</span></span>
Sin squared x equals 3 cos squared x
Answer:
Step-by-step explanation:
A copy machine can copy a report in 30 mins. When a second copy machine is used at the same time, the copying can be sone in 18 min. How long would it take the second copu machine to do the copying alone?
i have:
x=30
x+y=18
that would be -12..not right?
