Question

Exercitiile 16 si 17, va rog. Am trecut in clasa a 7-a.

Answer 1

$16a).7(x+2)-2(x-4)=6(x+2)-9 \\ 7x+14-2x+8=6x+12-9 \\ 7x-2x-6x=12-9-14-8 \\ -x=-19 \\ x=19 \\ b).10(x-1)-3(4x-7)-2=4(3x-5)+1 \\ 10x-10-12x+21-2=12x-20+1 \\ 10x-12x-12x=-20+1+10-21+2 \\ -14x=-28 \\ x= \frac{-28}{-14} \\ x=2$
$c).3(2x-7)-5(x-2)-3=2(x-7)+7 \\ 6x-21-5x+10-3=2x-14+7 \\ 6x-5x-2x=-14+7+21-10+3 \\ -x=7 \\ x=-7 \\ d).4(x-5)+3(3x-5)=2(2x+5)-9 \\ 4x-20+9x-15=4x+10-9 \\ 4x+9x-4x=10-9+20+15 \\ 9x=36 \\ x= \frac{36}{9} \\ x=4$
$e).5(2x+1)-8(1-x)=2(3x+2)+5 \\ 10x+5-8+8x=6x+4+5 \\ 10x+8x-6x=4+5-5+8 \\ 12x=12 \\ x= \frac{12}{12} \\ x=1 \\ f).3(5+4x)-6(x+2)=5(2x-1)-4 \\ 15+12x-6x-12=10x-5-4 \\ 12x-6x-10x=-5-4-15+12 \\ -4x=-12 \\ x= \frac{-12}{-4} \\ x=3$
$17a).18(2-x)+6(7x-12)=5(2x-1)-3 \\ 36-18x+42x-72=10x-5-3 \\ -18x+42x-10x=-5-3-36+72 \\ 14x=28 \\ x= \frac{28}{14} \\ x=2 \\ b).2(3x+4)-5(2x-3)=7(x-3)+11 \\ 6x+8-10x+15=7x-21+11 \\ 6x-10x-7x=-21+11-8-15 \\ -11x=-33 \\ x= \frac{-33}{-11} \\ x=3$
$c).4(9x-4)-3(3x-10)+11=4(2x-21)-5 \\ 36x-16-9x+30+11=8x-84-5 \\ 36x-9x-8x=-84-5+16-30-11 \\ 19x=-114 \\ x=- \frac{114}{19} \\ x=-6 \\ d).2(5x-4)+6(4x-3)+11=6(3x-4)-7 \\ 10x-8+24x-18+11=18x-24-7 \\ 10x+24x-18x=-24-7+8+18-11 \\ 16x=-16 \\ x=- \frac{16}{16} \\ x=-1$