SOLUTION: Really need help on this please:
Megan factored the expression 28x^2+x-15 as (4x-3)(7x+5). But when Jacob applied the FOIL principle and multiplied out (4x-3)(7x+5), he got 28x^
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-> SOLUTION: Really need help on this please:
Megan factored the expression 28x^2+x-15 as (4x-3)(7x+5). But when Jacob applied the FOIL principle and multiplied out (4x-3)(7x+5), he got 28x^
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Question 491531: Really need help on this please:
Megan factored the expression 28x^2+x-15 as (4x-3)(7x+5). But when Jacob applied the FOIL principle and multiplied out (4x-3)(7x+5), he got 28x^2-x-15; thus, Megan’s solution does not appear to check. Why is that? Please help Megan to understand this better. Explain your reasoning and correctly factor the original expression, if possible. If the expression is prime, so state. Found 2 solutions by oberobic, stanbon:Answer by oberobic(2304) (Show Source):
You can put this solution on YOUR website! 28x^2 +x -15
(4x -3)(7x + 5)
FOIL
28x +20x -21x -15
28x -x -15
.
(4x +3)(7x -5)
FOIL
28x -20x +21x - 15
28x +x -15
.
Done
You can put this solution on YOUR website! Megan factored the expression 28x^2+x-15 as (4x-3)(7x+5). But when Jacob applied the FOIL principle and multiplied out (4x-3)(7x+5), he got 28x^2-x-15; thus, Megan’s solution does not appear to check. Why is that?
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Megan did not factor correctly.
28x^2+x-15
28x^2 +21 -20x - 15
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7x(4x+3) -5(4x+3)
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(4x+3)(7x-5)
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Cheers,
Stan H.