a) 13/4x-1/2=9/8
8×13/4x-8×1/2=8×9/8
2×13x-4=9
26x-4=9
26x=9+4
26x=13
x=13/26= 1/2; verificarea;13/4×1/2-1/2=9/8, 13/8-1/2=9/8, /13-4/8=9/8, 9/8=9/8
b) calculeaza o treime din 9/10,
9/10×1/3=3/10.
apoi imulteste cu 2
2×3/10=3/5.
c)3×7/5=3/1×7/5=3×7/tot supra1×5= 21/5
notam prin x un numar;
x+6/5=21/5
x=21/5-6/5
x=21-6/ tot supra 5
x=15/5
x=3;
d) x/2+x/3=5/3
6×x/2+6×x/3=6×5/3
3x+2x=2×5
5x=10
x=10÷5
x=2. sper ca team ajutat bafta.
