Question

$(r+2)(r-5)+7r^2=(2r-3)(4r+1)$

Answer 1

r²-3r-10+7r²=8r²-10r-3
8r²-8r²-3r+10r-10+3=0
7r-7=0
r=7/7
r=1
comprobacion
(1+2)(1-5)+7(1²)=(2(1)-3)(4(1)+1)
(3)(-4)+7=(-1)(5)
-12+7=-5
-5=-5