Question

Please I need help with questions 2 and 3 and it’s very hard and I’m struggling with it and if you need to see the picture big then click on it and it will be big

Answer 1

2-first we change the scientific notations into fraction then do the calculation. at the end, you can change them to scientific notations
$8.42 \times {10}^{4} - 12 \times {10}^{2} \\ = 8420 - 0.012 = 8419.998$
hope this helps