Factoring by grouping usually pairs up the first 2 sets of expressions with the second 2 sets. Ours looks like this, then: 
. If we factor out the common x-squared in the first set of parenthesis, along with factoring out the common 5 in the second set, we get this: 
. Now the common expression that can be factored out is the (x-9). When we do that, here's what it looks like: 
. I'm not sure how far you are going with this. You could set each of those equal to 0 and solve for x in each case. The first one is easy. If x - 9 = 0, then x = 9. The second one involves the imaginary i since x^2 = -5. In that case, 
. Hopefully, in what I have given you, you can find what you're looking for.
Heike has 2 rocks. If the total weight of both rocks is 54.28
2 answers:
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Answer:
Step-by-step explanation:
Set up an equation to model the situation,
Distribute, multiply each term in the parenthesis with the term outside of the parenthesis. Don't forget the laws of exponents, when one multiplies two exponents, with the same base, then one adds the two exponents. A number with no exponential term is two the first degree meaning that it is to the power of one.