Question

How to show your work to solve  3r^2-16r-7=5

Answer 1

OK so   3r^2-16r-7=5
Subtract five from both sides
3r^2-16r-7-5=0
Add like terms
3r^2-16r-12=0
Factorise it, this means putting it into brackets
(3r + 2)(r - 6)
Find out what multiplies to make negative twelve but adds to make negative sixteen
However none of the terms do this so we put negatives next to the "r"s
(-3r + 2)(-1r - 6)
The answer is r=6

Answer 2

Answer:

Step 1: Subtract 5 from both sides.

3r2−16r−7−5=5−5

3r2−16r−12=0

Step 2: Factor left side of equation.

(3r+2)(r−6)=0

Step 3: Set factors equal to 0.

3r+2=0 or r−6=0

r=−2/3

or r=6

Answer:

r=−2/3

or r=6

Step-by-step explanation: