Question

Solve the equation. 78 = -2(m + 3) + m Question 11 options: –42 –28 –84 –72

Answer 1

Before we begin, note the following:
+ve * +ve = +ve
-ve * -ve = +ve
+ve * -ve = -ve
-ve * +ve = -ve

Now, for the given question:
The given equation is:
78 = -2(m+3) + m

To solve for m, we need to isolate m on one side of the equation and compute its value as follows:
78 = -2(m+3) + m
78 = -2m - 6 + m
m-2m = 78+6
-m = 84
m = 84/-1
m = -84

Answer 2

Hey there, hope I can help!

First switch the sides
$-2\left(m+3\right)+m=78$

$Expand\;-2\left(m+3\right)+m$

$-2\left(m+3\right)$
$\mathrm{Distribute\:parentheses\:using}: \:a\left(b+c\right)=ab+ac$
$Where\;a=-2,\:b=m,\:c=3$
$-2\cdot \:m-2\cdot \:3$

$\mathrm{Multiply\:the\:numbers:}\:2\cdot \:3=6 \ \textgreater \ -2m-6 \ \textgreater \ -2m-6+m$

Simply group the like terms
$-2m+m-6$

Add the similar elements which is -2m + m > -m > -m - 6 = 78

$\mathrm{Add\:}6\mathrm{\:to\:both\:sides} \ \textgreater \ -m-6+6=78+6$

Simplify
-m = 84

$\mathrm{Divide\:both\:sides\:by\:}-1 \ \textgreater \ \frac{-m}{-1}=\frac{84}{-1} \ \textgreater \ Simplify \ \textgreater \ m=-84$

Hope this helps!