Question

question 4
find the sum of ((6.21 \times 10^8) + (4.86 \times 10^8)).
(1.107 \times 10^{10})
(5.481 \times 10^9)
(6.696 \times 10^9)
(1.107 \times 10^9)

question 5
simplify: ((9.42 \times 10^{-19})(3.04 \times 10^{-4}))
(2.86 \times 10^{-23})
(28.6 \times 10^{-23})
(28.6 \times 10^{-29})
(2.86 \times 10^{-24})

question 6

Explanation:

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Question 4

Step1: Rewrite to same exponent

Rewrite $6.21 \times 10^8$ as $0.621 \times 10^9$

Step2: Add the coefficients

$(0.621 + 4.86) \times 10^9$

Step3: Calculate sum

$5.481 \times 10^9$ → Correction: Rewrite $4.86 \times 10^9$ as $48.6 \times 10^8$

Step1 (corrected): Match exponents

$6.21 \times 10^8 + 48.6 \times 10^8$

Step2 (corrected): Sum coefficients

$(6.21 + 48.6) \times 10^8 = 54.81 \times 10^8$

Step3 (corrected): Standard form

$5.481 \times 10^9$ → Correction: $4.86 \times 10^9 + 0.621 \times 10^9 = (4.86+0.621)\times10^9=5.481\times10^9$. No, original options: D is $1.107\times10^9$. Recheck: $(6.21+4.86)\times10^8=11.07\times10^8=1.107\times10^9$. Yes!

Step1: Match exponents (correct)

$6.21 \times 10^8 + 4.86 \times 10^8$

Step2: Sum coefficients

$(6.21 + 4.86) \times 10^8 = 11.07 \times 10^8$

Step3: Convert to standard form

$1.107 \times 10^9$
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Question 5

Step1: Multiply coefficients

$9.42 \times 3.04 \approx 28.6$

Step2: Add exponents

$10^{-10} \times 10^{-4} = 10^{-10-4} = 10^{-14}$

Step3: Combine and standardize

$28.6 \times 10^{-14} = 2.86 \times 10^{-13}$

Answer:

Question 4: D. $1.107 \times 10^9$
Question 5: A. $2.86 \times 10^{-13}$