Question

помогите пожалуйста разобраться в этих пропорциях

Answer 1

3) 3x=4-1
3x=3
X=1
4) 6x+1=10
6x=10-1
6x=9
X=3/2
5) 240=3(25x+5)
80=25x+5
-25x=5-80
-25x=-75
X=3
6) 5x-14=6
5x=6+14
5x=20
X=4

Answer 2

▪3)

$frac{2.7}{9} = frac{1 frac{1}{5} }{3x + 1} \ 2.7(3x + 1) = 9 times 1 frac{1}{5} \ 2.7(3x + 1) = frac{9 times 6}{5} \ 2.7(3x + 1) = frac{54}{5} : : : : : | div 2.7 \ 3x + 1 = frac{54 times 10}{5 times 27} \ 3x + 1 = 2 times 2 \ 3x = 4 - 1 \ 3x = 3 : : : : : | div 3 \ x = 1$

▪4)


$frac{1 frac{4}{5} }{2.5} = frac{7.2}{6x + 1} \ 6x + 1 = frac{2.5 times 7.2}{1 frac{4}{5} } \ 6x + 1 = frac{18}{ frac{9}{5} } \ 6x + 1 = frac{18 times 5}{9} \ 6x = 2 times 5 - 1 \ 6x = 9 \ x = frac{9}{6} = frac{3}{2} = 1 frac{1}{2} = 1.5$

▪5)

$frac{6}{1 frac{4}{5} } = frac{3x + 0.6}{2.88} \ 3x + 0.6 = frac{6 times 2.88}{1 frac{4}{5} } \ 3x + 0.6 = frac{17.28}{ frac{9}{5} } \ 3x + 0.6 = frac{17.28 times 5}{9} \ 3x = 9.6 - 0.6 \ x = 9 div 3 \ x= 3$

▪6)

$frac{ frac{3}{8} }{0.75} = frac{0.6}{x - 2.8} \ frac{3}{8} (x - 2.8) = 0.75 times 0.6 \ frac{3}{8} (x - 2.8) =0.45 : : : : : | div frac{3}{8} \ x - 2.8 = frac{45 times 8}{100 times 3} \ x - 2.8 = frac{15 times 2}{25} \ x = frac{6}{5} + 2.8 = 1 frac{1}{5} + 2.8 = 1.2 + 2.8 = 4$