Read the following passage and answer questions 19, 20, 21, 22, 23 & 24.
Directions - Study this lesson then answer the exam questions that follow.
1. There is a certain order of operations in mathematics. For example, in the expression 3 + 2(4) the product of 2(4) must be done first, then that product should be added to 3. Multiplication is done before either addition or subtraction. Thus, 3 + 2(4) = 2 + 8 = 10.
2. In the expression 14/2 - 1, the quotient 14/2 must be found first. Then the 1 is subtracted from that quotient. Division is done before either addition or subtraction. Thus, 14/2 - 1 = 7 - 1 = 6.
3. If x = 5 and y = 3, then what is the value of 2x2 - 4y? Recall from lesson 1 that 2x2 - 4y means 2*x*x - 4*y. Thus, 2x2 - 4y = 2*5*5 - 4*3 = 50 - 12 = 38.
Note: The general rule is first to multiply or divide and then add or subtract. However, if some terms are enclosed in parentheses, then we calculate within the parenthesis first.