Answer:
Step-by-step explanation:
r²+8r=−7
Step 1: Subtract -7 from both sides.
r²+8r−(−7)=−7−(−7)
r²+8r+7=0
Step 2: Use quadratic formula with a=1, b=8, c=7.
r=[tex]r=\frac{-b+or-\sqrt{-4ac} }{2a}[/tex]
[tex]r=\frac{-8+or-\sqrt{(8})^2-4(1)(7) }{2(1)}[/tex]
