ПОЖАЛУЙСТА,РЕШИТЕ!!!Решите уравнение: 1) -5/12х=0
2) 5,4(х+6,3)=0
3) (х-3)(х+4)=0
4) 23,5 |х|=0
(6 класс)

Step-by-step explanation:

1). x = 0 ⇒ x = 0

2). 5,4 ( x + 6,3 ) = 0 ⇒ x + 6,3 = 0 ⇒ x = - 6,3

3). ( x - 3 )( x + 4 ) = 0 ⇒ x - 3 = 0 или x + 4 = 0 ⇒ x = 3 или x = - 4

4). 23,5 | x | = 0 ⇒ | x | = 0 ⇒ x = 0

The total nom of  code that can be used is equal to 5+3 = 8

For every 8 cars there are 7 trucks

Therefore,

Cars:Truck=8:7

Answer is B)8:7

The solution is in the following image

The answer is in the image 

Speed=Distance/time

Here,

distance=15m

time=1sec

speed=15/1=15m/sec

Distance=Speed*time

time=15min=15*60sec=900sec

Distance travelled in 15 min=15*900=13,500m

=13500/1000 km=13.5Km

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

The answer is in the image 

The answer is in the image 

Let the father's age be x and son's be y

10 years before-

Father age=x-10

sons age=y-10

Given,

x-10=10(y-10)

x-10=10y-100

Given present age of father=40

therefore,

x=40

40-10=10y-100

10y-100=30

10y=130

y=130/10

y=13

Therefore present age of son=13years