IsadiraEmmycour7ti1n
Answered

The work of a student to solve a set of equations is shown:


Equation 1: m = 8 + 2n

Equation 2: 3m = 4 + 4n




Step 1:

−3(m) = −3(8 + 2n) [Equation 1 is multiplied by −3.]

3m = 4 + 4n [Equation 2]


Step 2:

−3m = −24 − 6n [Equation 1 in Step 1 is simplified.]

3m = 4 + 4n [Equation 2]


Step 3:

−3m + 3m = −24 − 6n + 4n [Equations in Step 2 are added.]


Step 4:

0 = −24 − 2n


Step 5:

n = −12



In which step did the student first make an error?


Step 4


Step 3


Step 2


Step 1

Verified Answer :

marydimpar

I think the student first made an error on step 1 because why is it multiplied by -3. To be more precise, where did the student get the -3 from?

Answer:

Step 3

Step-by-step explanation:

Hello

the student made a mistake in the step number 3.

let´s see

in the step number 1 he multiplied by -3 in order to add this new equation with  equiation 2 and then eliminate the terms with m

Step one

-3(m)=-3(8+2n)

-3m= -24 - 6 n,  it is ok

in step two he simplified, he did it well.

in the step 3  he added the equations

 -3m = -24-6n

  3m = 4   +4n

_____________

    0   = -20-2n

he did not add properly -24+4, here , he made his first mistake.

step 4 is already wrong

continuing..to find n

0= -20-2n

20=-2n

n=-10

Have a great day

 

Related Questions