1. Evaluate 1/2a^-4 b^2 for a=-2 and b=4
A. 2
B. 1/2
C. 3
D. 4
2. Simplify. Write in scientific notation. (9x10^-3)^2
A. 8.1x10^-5
B. 8.1x10^-4
C. 8.1x10^-3
D. 8.1x10^-6
3. Simplify. Write in scientific notation. 0.5(8x10^5)
A. 8x5^5
B. 4x5^5
C. 8x10^5
D. 4x10^5
4. Write in standard notation. 6.12x10^2
A. 6,120
B. 612
C. 61,200
D. 6.12
5. Write in scientific notation. 0.0042
A. 42x10^-2
B. 4.2x10^-4
C. 4.2x10^-3
D. .42x10^-4
will gladly check your work
Oh, sorry.
D A D B C
Hello? Are they correct?
Redo #1, the rest are correct
1. To evaluate 1/2a^-4 b^2 for a=-2 and b=4, we substitute the given values into the expression. Start by replacing a with -2 and b with 4:
1/2(-2)^-4 * (4)^2
Next, simplify the expressions inside the parentheses:
1/2(1/(-2)^4) * (16)
We now have to simplify the exponent (-2)^4:
1/2(1/16) * 16
Simplify the fractions:
1/32 * 16
Perform the multiplication:
16/32
And simplify the fraction:
1/2
So, the answer is B. 1/2.
2. To simplify (9x10^-3)^2 and write it in scientific notation, we need to follow these steps:
First, square the entire expression:
(9x10^-3)^2 = (9^2) x (10^-3)^2
Simplify the arithmetic inside the parentheses:
81 x 10^-6
Next, rewrite 10^-6 in scientific notation:
81 x 1x10^-6
Multiply the numbers:
81 x 10^-6
Therefore, the answer is D. 8.1x10^-6.
3. To simplify 0.5(8x10^5) and write it in scientific notation, follow these steps:
Multiply 0.5 by 8:
0.5 x 8 = 4
Multiply 10^5 by 10^0:
10^5 x 10^0 = 10^5
Combine the results:
4 x 10^5
Therefore, the answer is D. 4x10^5.
4. To write 6.12x10^2 in standard notation, you need to multiply the decimal 6.12 by the power of 10 represented by the exponent 2:
6.12 x 10^2 = 6.12 x 100
Perform the multiplication:
612
Therefore, the answer is A. 6,120.
5. To write 0.0042 in scientific notation, we need to move the decimal point so that there is one non-zero digit to the left of the decimal. In this case, we move it four places to the right:
0.0042 = 4.2 x 10^-3
Therefore, the answer is C. 4.2x10^-3.