Question

1) DETERMINE O VALOR TERMO REPRESENTADO PELAS INCÒGNITAS ABAIXO:

A) 4X /30 = 120/2

B) 24/Y =6/8

C) 25/Y=4/8

D) 9X/8 =36/4

2) CALCULE O VALOR DE X NAS PROPORÇÕES ABAIXO

A) 7/3 =X/12

B) 2X/15 =6/9

C) 2X/15 =6/9

D) X +1 /5 =X/3

3) 60 REPRESENTA 20% DE QUAL NUMÈRO ABAIXO:

A) 150 B)200 C)300 D)400

4) 45 REPRESENTA 15% DE QUAL NUMÈRO ABAIXO;

A) 300 B) 200 C)400 D)150

POR FAVOR ME AJUDEMMM!!!!!

Answer 1

Explicação passo-a-passo:

1)

a)

$\sf \dfrac{4x}{30}=\dfrac{120}{2}$

$\sf 2\cdot4x=30\cdot120$

$\sf 8x=3600$

$\sf x=\dfrac{3600}{8}$

$\sf \red{x=450}$

b)

$\sf \dfrac{24}{y}=\dfrac{6}{8}$

$\sf 6y=24\cdot8$

$\sf 6y=192$

$\sf y=\dfrac{192}{6}$

$\sf \red{y=32}$

c)

$\sf \dfrac{25}{y}=\dfrac{4}{8}$

$\sf 4y=25\cdot8$

$\sf 4y=200$

$\sf y=\dfrac{200}{4}$

$\sf \red{y=50}$

d)

$\sf \dfrac{9x}{8}=\dfrac{36}{4}$

$\sf 4\cdot9x=8\cdot36$

$\sf 36x=288$

$\sf x=\dfrac{288}{36}$

$\sf \red{x=8}$

2)

a)

$\sf \dfrac{7}{3}=\dfrac{x}{12}$

$\sf 3x=7\cdot12$

$\sf 3x=84$

$\sf x=\dfrac{84}{3}$

$\sf \red{x=28}$

b)

$\sf \dfrac{2x}{15}=\dfrac{6}{9}$

$\sf 9\cdot2x=15\cdot6$

$\sf 18x=90$

$\sf x=\dfrac{90}{18}$

$\sf \red{x=5}$

c)

$\sf \dfrac{2x}{15}=\dfrac{6}{9}$

$\sf 9\cdot2x=15\cdot6$

$\sf 18x=90$

$\sf x=\dfrac{90}{18}$

$\sf \red{x=5}$

d)

$\sf \dfrac{x+1}{5}=\dfrac{x}{3}$

$\sf 5x=3\cdot(x+1)$

$\sf 5x=3x+3$

$\sf 5x-3x=3$

$\sf 2x=3$

$\sf x=\dfrac{3}{2}$

$\sf \red{x=1,5}$

3)

$\sf ~20\%~~~~~\Rightarrow~~~~60$

$\sf 100\%~~~~\Rightarrow~~~~~x$

$\sf 20x=100\cdot60$

$\sf 20x=6000$

$\sf x=\dfrac{6000}{20}$

$\sf \red{x=300}$

Letra C

4)

$\sf ~15\%~~~~~\Rightarrow~~~~45$

$\sf 100\%~~~~\Rightarrow~~~~~x$

$\sf 15x=100\cdot45$

$\sf 15x=4500$

$\sf x=\dfrac{4500}{15}$

$\sf \red{x=300}$

Letra A