Mathematics: Anna and belle are asked to solve −2x − 15 = 6x + 9. identify where one of them made an error. anna belle −2x − 15 = 6x + 9 −2x − 15 −6x = 6x + 9 −6x −8x − 15 = 9 −8x − 15 + 15 = 9 + 15 −8x = 24 negative 8x over negative 8 equals 24 over negative 8 x = −3 −2x − 15 = 6x + 9 −2x − 15 + 2x = 6x + 9 + 2x −15 = 8x + 9 −15 + 9 = 8x + 9 + 9 −6 = 8x negative 6x over 8 equals 8x over 8 negative two-thirds

If she used rounding she would’ve gotten -25×10 equals -250...

Anna and belle are asked to solve −2x − 15 = 6x

xxaurorabluexx

11.03.2022

Belle is wrong.

Step-by-step explanation:

The given expression is

-2x-15=6x+9

The steps Anna did are

$-2x-15=6x+9\\-2x-15-6x=6x+9-6x\\-8x-15=9\\-8x-15+15=9+15\\-8x=24\\\frac{-8x}{-8}=\frac{24}{-8} \\x=-3$

If you look carefuly, you would notice that Anna didn't make any mistakes, her steps and result is correct.

Belle steps are

$-2x-15=6x+9\\-2x-15+2x=6x+9+2x\\-15=8x+9\\-15+9=8x+9+9$

Notice that this step is wrong, because she's not adding -9 to eliminate that term.

-6=8x , this step is also wrong, because 9 + 9 = 18.

Therefore, Belle is wrong.

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