Toán

\(5(2x+3) (x+2)- 2(5x-4) (x-1)=75\)

\(\Leftrightarrow 10 x^{2}+20 x+15 x+30-10 x^{2}+10 x+8 x-8=75\)

\(\Leftrightarrow 53 x+22=75 \Leftrightarrow x=1\)

\(\begin{aligned} &\text 5(2 x+3)(x+2)-2(5 x-4)(x-1)=75\\ &\Leftrightarrow=5\left(2 x^{2}+7 x+6\right)-2\left(5 x^{2}-9 x+4\right)=75\\ &\Leftrightarrow=10 x^{2}+35 x+30-10 x^{2}+18 x-8=75\\ &\text { <=> } 53 x+22=75\\ &\Leftrightarrow \Rightarrow 53 x=53\\ &<=>x=1 \end{aligned}\)

5(2x + 3 )( x + 2 ) - 2( 5x - 4 )( x - 1 ) = 75

<=> 5( 2x2 + 7x + 6 ) - 2( 5x2 - 9x + 4 ) = 75

<=> 10x2 + 35x + 30 - 10x2 + 18x - 8 = 75

<=> 53x + 22 = 75

<=> 53x = 53

<=> x = 1