Question

Rezolvati ecuatiile :
a) 2x+7=15
b) 3x-11=21
c) 5+2(x-1) =12
d) 3(x-3)-8=20
e) 15-4(x+1)=10
f )x- 2 supra 3 = 1pe langa si 1supra 15
g) 3 supra 4 -x = 1 supra 12
h) 7 supra 18 + x = 19 supra 15
i) 9 • x = 12
j) x • 4 supra 25 = 16 supra 5
k) 35 supra 24 : x = 2 , (3)
l ) 4x+5 = x + 13
m ) 11x + 17 = 2 x + 21
n) 3x - 1 supra 2 = 3 supra 7 - 4 x
o ) 3 supra 22 x - 1 supra 2 = 6 supra 55 + 1 supra 11 x
p) x supra 2 - x supra 3 = 7 supra 6

Answer 1

$a)2x + 7 = 15$

$2x = 15 - 7$

$2x = 8$

$x = \frac{8}{2}$

$x = 4$

$b)3x - 11 = 21$

$3x = 21 + 11$

$3x = 32$

$x = \frac{32}{3}$

$c)5 + 2(x - 1) = 12$

$5 + 2x - 2 = 12$

$2x = 12 - 5 + 2$

$2x = 9$

$x = \frac{9}{2}$

$d)3(x - 3) - 8 = 20$

$3x - 9 - 8 = 20$

$3x - 17 = 20$

$3x = 20 + 17$

$3x = 37$

$x = \frac{37}{3}$

$e)15 - 4(x + 1) = 10$

$15 - 4x - 4 = 10$

$- 4x = 10 - 15 + 4$

$- 4x = - 1 \: | \times ( - 1)$

$4x = 1$

$x = \frac{1}{4}$

$f)x - \frac{2}{3} = 1\frac{1}{15}$

$x - \frac{2}{3} = \frac{1 \times 15 + 1}{15}$

$x - \frac{2}{3} = \frac{16}{15}$

$15x - 10x = 16$

$5x = 16$

$x = \frac{16}{5}$

$g) \frac{3}{4} - x = \frac{1}{12}$

$9 - 12x = 1$

$- 12x = 1 - 9$

$- 12x = - 8 \: | \div ( - 4)$

$3x = 2$

$x = \frac{2}{3}$

$h) \frac{7}{18} + x = \frac{19}{15}$

$35 + 90x = 114$

$9x = 114 - 35$

$9x = 79$

$x = \frac{79}{9}$

$i)9x = 12$

$x = \frac{12}{9}$

$x = \frac{4}{3}$

$j)x \times \frac{4}{25} = \frac{16}{5}$

$\frac{4x}{25} = \frac{16}{5}$

$4x \times 5 = 25 \times 16$

$20x = 400$

$x = \frac{400}{20}$

$x = 20$

$k) \frac{35}{24} \div x = 2.(3)$

$\frac{35}{24} \times \frac{1}{x} = \frac{23 - 2}{9}$

$\frac{35}{24x} = \frac{21}{9}$

$\frac{35}{24x} = \frac{7}{3}$

$24x \times 7 = 3 \times 35$

$168x = 105$

$x = \frac{105}{168}$

$x = \frac{35}{56}$

$x = \frac{5}{8}$

$l)4x + 5 = x + 13$

$4x - x = 13 - 5$

$3x = 8$

$x = \frac{8}{3}$

$m)11x + 17 = 2x + 21$

$11x - 2x = 21 - 17$

$9x = 4$

$x = \frac{4}{9}$

$n)3x - \frac{1}{2} = \frac{3}{7} - 4x$

$3x + 4x = \frac{3}{7} + \frac{1}{2}$

$7x = \frac{6}{14} + \frac{7}{14}$

$7x = \frac{6 + 7}{14}$

$7x = \frac{13}{14}$

$7x \times 14 = 13$

$98x = 13$

$x = \frac{13}{98}$

$o) \frac{3}{22x} - \frac{1}{2} = \frac{6}{55} + \frac{1}{11x}$

$\frac{3}{22} - \frac{x}{2} = \frac{6x}{55} + \frac{1}{11}$

$\frac{15}{110} - \frac{55x}{110} = \frac{12x}{110} + \frac{10}{110}$

$15 - 55x = 12x + 10$

$- 55x - 12x = 10 - 15$

$- 67x = - 5 \: | \times ( - 1)$

$67x = 5$

$x = \frac{5}{67}$

$p) \frac{x}{2} - \frac{x}{3} = \frac{7}{6}$

$3x - 2x = 7$

$x = 7$