Question

Помогите плиззз решить уравнение

Answer 1

4. $\displaystyle \frac{x+4}{4}-\frac{x-3}{6} =2$
$\displaystyle \frac{6(x+4)-4(x-3)}{4*6} =\frac{2}{1}$
Перемножим дроби по правилу пропорции
$\displaystyle (6x+24-4x+12)*1=24*2$
$\displaystyle 2x+36=48$
$\displaystyle 2x=48-36$
$\displaystyle 2x=12|:2$
$\displaystyle x=6$
Проверка
$\displaystyle \frac{6+4}{4}-\frac{6-3}{6} =2$
$\displaystyle \frac{10}{4}-\frac{3}{6} =2$
$\displaystyle \frac{5}{2}-\frac{1}{2} =2$
$\displaystyle 2,5-0,5 =2$
$\displaystyle 2=2$
Верно!
Ответ: х = 6

5. $\displaystyle \left \{ {{3(2x-y)-2(x-y)=1} \atop {4x-5(x+2y)=51}} \right.$
$\displaystyle \left \{ {{6x-3y-2x+2y=1} \atop {4x-5x-10y=51}} \right.$
$\displaystyle \left \{ {{4x-y=1} \atop {-x-10y=51}} \right.$
$\displaystyle \left \{ {{y=4x-1} \atop {-x-10(4x-1)=51}} \right.$
$\displaystyle \left \{ {{y=4x-1} \atop {-x-40x+10=51}} \right.$
$\displaystyle \left \{ {{y=4x-1} \atop {-41x=51-10}} \right.$
$\displaystyle \left \{ {{y=4x-1} \atop {-41x=41|:(-41)}} \right.$
$\displaystyle \left \{ {{y=4*(-1)-1} \atop {x=-1}} \right.$
$\displaystyle \left \{ {{y=-4-1} \atop {x=-1}} \right.$
$\displaystyle \left \{ {{y=-5} \atop {x=-1}} \right.$
Проверка:
$\displaystyle \left \{ {{3(2*(-1)-(-5))-2((-1)-(-5))=1} \atop {4*(-1)-5((-1)+2*(-5))=51}} \right.$
$\displaystyle \left \{ {{3(-2+5)-2(-1+5)=1} \atop {-4-5(-1-10)=51}} \right.$
$\displaystyle \left \{ {{3*3-2*4=1} \atop {-4-5*(-11)=51}} \right.$
$\displaystyle \left \{ {{9-8=1} \atop {-4+55=51}} \right.$
$\displaystyle \left \{ {{1=1} \atop {51=51}} \right.$
Верно!
Ответ: (х,y) = (-1;-5)