Question

1)решите уравнение x/5-1/5=5/2-x/2+3x/4 2)упростите выражение 3х(х+y+c)-3y(x-y-c)-3c(x+y-c)

Answer 1

1)

$frac{x}{5}-frac{1}{5}=frac{5}{2}-frac{x}{2}+3frac{x}{4}\ frac{x-1}{5}=frac{10+x}{4}\ 4x-4=50+5x\ x=-54$

2)

$3x(x+y+c)-3y(x-y-c)-3c(x+y-c)=3x^2+3xy+\ +3xc-3xy+3y^2+3yc-3xc-3yc+3c^2=3x^2+3y^2+3c^2$