I don't under stand what is wrong.

Mathematics

1 answer:

MAXImum [283]2 years ago

4 0

Answer:

In the first step, there is an issue when distributing the -3 to the terms inside of the parentheses. When multiplying the -3 to the -5, you would get an answer of +15, not -15.

The full correct process is:

(4m + 9) - 3(2m - 5) = 4m + 9 - 6m + 15

= 4m - 6m + 9 + 15

= -2m + 24

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-3+9x>87 or -x-9>-17

Alex_Xolod [135]

Answer:

$\large\boxed{x\in(-\infty,\ 8)\ \cup\ (10,\ \infty)}$

Step-by-step explanation:

$-3+9x>87\qquad\text{add 3 to both sides}\\\\9x>90\qquad\text{divide both sides by 9}\\\\\boxed{x>10}\to(1)\\\\-x-9>-17\qquad\text{add 9 to both sides}\\\\-x>-8\qquad\text{change the signs}\\\\\boxed{x10\ or\ x$