Question

determinati,in fiecare exercitiu,numarul natural x, stiind ca:
1)3*x+1/2*x+5 din 252 este 20;
2)x/3 din x+1 este 4.
Nu am invatat cu numere negative.
Va rooooooooog mult de tot!

Answer 1

a)3x+1/2x+5x252=20⇒252(3x+1)/2x+5=20
756x+252/2x+5=20⇒20(2x+5)=756x252⇒40x+100=190512⇒40x=190512-100⇒40x=190412⇒x=190412/40⇒x=4760.3
b)x/3x x(x+1)=4⇒x(x+1)/3x=4⇒x²+x/3x=4⇒x²+x=3xx4⇒
x²+x=12x⇒x²-12x+x=0⇒x²-11x=0
a=1
b=-11
c=0
Δ=b²-4ac⇒(-11)²-4×1×0⇒Δ=121-0⇒Δ=121⇒√Δ=√121⇒Δ=11⇒
x1x2=-b+-√Δ/2a
x1=11+11/2⇒22/2⇒x1=11
x2=11-11/2⇒0/2⇒x2=0
sucees