Question

42 = -48 + 3r
This is some random stuff the teacher didn’t teach us about

Answer 1

Answer:

$42 = - 48 + 3r$

add 48 to either sides:

$42 + 48 = ( - 48 + 3r) + 48 \\ 90 = 3r \\3r = 90$

divide all sides by 3:

$\frac{3r}{3} = \frac{90}{3} \\ \\ { \boxed{ \boxed{r = 30}}}$

Answer 2

Answer:

r = 30

Step-by-step explanation:

42 = -48 + 3r

• First, we will add 48 to both sides so that r can be isolated

42 + 48 = -48 + 48 + 3r

• Then, we will add

90 = 3r

• Then to isolate r, we have to get rid of the 3
• To get rid of the 3, we will divide by 3 on both sides

$\frac{90}{3} =\frac{3r}{3}$

• Then, divide

30 = r