A3a
Practice - Simplifying Expressions
TRY TO ANSWER IN TWO AND A HALF MINUTES.
QUESTIONS
QUESTIONS
1. Simplify 7x ² + 5y ² - 4y ² + 2x.
2. You have an expression 1/((x)(x-2)). For what values of x is this expression not defined?
3. Write in the simplest form: 4x - 5xy - 6y + 6xy - 2x - xy.
4. Simplify the following: 3x³ + x + 2x³ - 4x² +14y -2(y + x).
5. Simplify 4x - 2(3x - 9).
6. Solve 3(x+2) = 2(2-x).
7. Simplify the expression -3(x² + 2x +3x).
ANSWERS
1. The only two terms you can combine are 5y ² minus 4y ² , to get y ². So the answer is 7x ² + y ² + 2x.
2. An expression is not defined if it involves division by zero. In this case, x = 0 and x = 2 fit this criterion.
3. Combine like terms: 2x + 10xy - 6y.
4. First break out the two terms inside the parentheses to (-2y - 2x). Then simplify the rest to 5x³ - 4x² -x + 12y.
5. Begin by multiplying the terms inside the parentheses. This gives 4x - 6x + 18 = 18 - 2x.
6. Expand to 3x + 6 = 4 - 2x, then simplify to 5x = -2, then x = -(5/2).
7. Using the PEMDAS order of operations, first simplify the part of the expression within the parentheses to (2x²+ 4x). Then multiply this by -3 to get -6x² -12x.
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