Đáp án:
Giải thích các bước giải:
$a)(\dfrac{5}{2}x-3).2=7x+16$
$⇔5x-6=7x+16$
$⇔2x=-22$
$⇔x=-11$
$b)5.(-3x-7)+4x.(x-5)=4x^2+16.(x-4)$
$⇔-15x-35+4x^2-20x=4x^2+16x-64$
$⇔-35x-35=16x-64$
$⇔-51x=-29$
$⇔x=\dfrac{29}{51}$
$c)(3x-7).5+40x-35=5.(-20x+16)$
$⇔15x-35+40x-35=-100x+80$
$⇔55x-70=-100x+80$
$⇔155x=150$
$⇔x=\dfrac{30}{31}$