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a) what did the student do wrong, explain why they are incorrect
b) demonstrate and explain the correct way to answer the question.
lauren says that two expressions 3x+4(2x+5) and 6x +5x +5 are equivalent. simplify the expressions to determine whether or not lauren is correct. substitute a value for x to see if she is right.
students she is correct because both equal 11x +5. i subsisted x=2 and got 27 for both

A) what did the student do wrong, explain why they are incorrect  

B) Demonstrate and explain the correct way to answer the question.  

Lauren says that two expressions 3x+4(2x+5) and 6x +5x +5 are equivalent. Simplify the expressions to determine whether or not Lauren is correct. Substitute a value for x to see if she is right.

3x+8x+20 = 6x+5x+5

11x+20 = 11x+5

She is wrong

Students She is correct because both equal 11x +5. I substituted x=2 and got 27 for both

She is wrong because 27 will be the answer for ' 11x+5' only. The correct method should be

x=-15

Step-by-step explanation:

➷ A) The student did not expand properly for the first expression

B) (3x + 4)(2x + 5) = 6x^2 + 15x + 8x + 20 = 6x^2 +23x + 20

6x^2 + 23x + 20 = 11x + 5

Substitute 2 in:

6(2)^2 + 23(2) + 20 = 90

11(2) + 5 = 27

Lauren is incorrect as both expressions do not equal each other. When 2 is substituted, only the second expression equals 27

➶ Hope This Helps You!

➶ Good Luck (:

➶ Have A Great Day ^-^

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