Question

1.Rezolvati in multimea numerelor rationale ecuatiile:
a)7x+1=2x+11
b)2x-6=8x-15
c)10x-41=3x-27
d)14x+7=20x-17
e)5x+17=13x-15
f)15x+12=11x+9.

Answer 1

$1a)7x+1=2x+11 \\ 7x-2x=11-1 \\ 5x=10 \\ x= \frac{10}{5} \\ x=2 \\ b).2x-6=8x-15 \\ 2x-8x=-15+6 \\ -6x=-9 \\ x= \frac{9}{6} \\ x= \frac{3}{2}$
$c).10x-41=3x-27 \\ 10x-3x=-27+41 \\ 7x=14 \\ x= \frac{14}{7} \\ x=2 \\ d).14x+7=20x-17 \\ 14x-20x=-17-7 \\ -6x=-24 \\ x= \frac{-24}{-6} \\ x=4$
$e).5x+17=13x-15 \\ 5x-13x=-15-17 \\ -8x=-32 \\ x= \frac{-32}{-8} \\ x=4 \\ f).15x+12=11x+9 \\ 15x-11x=9-12 \\ 4x=-3 \\ x=- \frac{3}{4}$