Question

Choose all equations that are true.

9.21 × 103 = 921
9.21 × 101 = 92.1
0.921 × 100 = 921
0.921 × 104 = 9,210
0.0921 × 102 =9.21

Answer 1

To determine which equations are true, we need to evaluate each equation and consider the rules of multiplying by powers of 10. 9.21 × 10³ = 921 is false, 9.21 × 10¹ = 92.1 is true, 0.921 × 10² = 921 is false, 0.921 × 10⁴ = 9,210 is true, and 0.0921 × 10² = 9.21 is true.

Step-by-step explanation:

To determine which equations are true, we need to evaluate each equation.

1. 9.21 × 103 = 921 : This equation is false because when multiplying a number by a power of 10, the exponent indicates how many places the decimal point should be moved. 103 means moving the decimal point three places to the right. Multiplying 9.21 by 103 gives 9210.
2. 9.21 × 101 = 92.1 : This equation is true. When multiplying a number by a power of 10, the exponent indicates how many places the decimal point should be moved. In this case, 101 means moving the decimal point one place to the right. Multiplying 9.21 by 101 gives 92.1.
3. 0.921 × 102 = 921 : This equation is false because when multiplying a number by a power of 10, the exponent indicates how many places the decimal point should be moved. 102 means moving the decimal point two places to the right. Multiplying 0.921 by 102 gives 92.1.
4. 0.921 × 104 = 9,210 : This equation is true. When multiplying a number by a power of 10, the exponent indicates how many places the decimal point should be moved. In this case, 104 means moving the decimal point four places to the right. Multiplying 0.921 by 104 gives 9,210.
5. 0.0921 × 102 = 9.21 : This equation is true. When multiplying a number by a power of 10, the exponent indicates how many places the decimal point should be moved. In this case, 102 means moving the decimal point two places to the right. Multiplying 0.0921 by 102 gives 9.21.