How is this solved?
r2 + 2r = 80

r=20

Step-by-step explanation:

1.) r2+r2=r4

2.)r4=80

3.)80/4=20

4.)r=20

8,-10

Step-by-step explanation:

r²+2r=80

r²+2r-80=0

r²+(10-8)r-80=0

r²+10r-8r-80=0

r(r+10)-8(r+10)=0

(r-8)(r+10)=0

either, or,

r-8=0 r+10=0

r=8 r=-10

actually your concept is wrong

step-by-step explanation:

150% of x =300

150x=300×100

x=(300×100)÷150

x=200