Algebra: Chapter 3-7
Formulas
Formulas that use more than 1 letter are often called literal equation. Use the formula and solve for the desired variable by treating all other variables as if they are constants or coefficients. Constants are separated by + and − symbols whereas coefficients are like `2x`, the 2 is a coefficient.
Just solve these like any other equation using the strategies from yesterday
- Multiply both sides to clear fractions or decimals, if necessary.
- Collect like terms on each side, if necessary.
- Use the addition property to move the variable to one side and all other terms to the other side of the equation.
- Collect like terms again, if necessary.
- Use the multiplication property to solve for the variable.
Intro to Algebra: Chapter 2-5
Multiplication of Rational Numbers
Today is easy because the rules for multiplication and division are simple. When multiplying 2 numbers AND if the SIGNS are the same, the product is ALWAYS positive. If the signs are different, them the product is ALWAYS negative. This is pretty straightforward. Division follows the same rules as multiplication.
2 rational numbers whose product is 1 are called multiplicative inverses or reciprocals of each other. Just flip the rational expression over and keep the same sign. For example, the reciprocal of `2/3` or `m/n` is `3/2` and `n/m`.
Remember too, to divide rational numbers, sometimes its easier to express them as improper fractions, then convert the 2nd term to its reciprocal and change the `/` to a `∗`.