Question

(2x-7)^2-11(2x-7)+30=0

Answer 1

(2x-7)²-11(2x-7)+30=0
4x²-28x+49-22x+77+30=0
4x²-50x+156=0
2x²-25x+78=0
D=(-25)²-4*78*2=625-624=1=1²
$x_{1}= frac{-(-25)- sqrt{1} }{2*2} = frac{25-1}{4} = frac{24}{4} =6 \ x_{2}= frac{-(-25)+sqrt{1} }{2*2} = frac{25+1}{4} = frac{26}{4} =6,5$