Answer:

Step-by-step explanation:
By logarithm rules

Answer:
The value of r=
The value of x=
Step-by-step explanation:
Given that,
A) 
Now,

8(2r-2)=9(7r+10)
16r-16=63r+90
-16-90=63r-16r
-(16+90)=47r
-106=47r
r=
B) 
Now,

5(x+5)=9[3(x-2)-1]
5x+25=9[3x-6-1]
5x+25=9[3x-7]
5x+25=27x-63
25+63=27x+5x
83=32x
x=
Recall your d = rt, distance = rate * time
let's say we have two cars, A and B, B has a speed rate of "r", so A is the faster one and has a speed rate of " r + 10 "
they both are 300 miles apart after 3hrs, after 3hrs, car has been running for 3hrs, and car B has also been running for 3hrs, so their time is the same
we know their distances added up, is 300miles, so if car B covered say, "d" distance on those 3hrs, car A covered the slack, " 300 - d "

solve for "r"
Meters: 3.9
centimeters: 390
i hoped i help :)
You can either do this on the calculator, or in your head. As its a larger number, it is worth doing it on the calculator.
413/14= 29.5
The alternative method is to list all of the tens multiples, and the smaller multiples when you're getting close to the answer, and this will be able to help you.
14x10= 140
14x20=280
14x30= 420 (which is slightly too big)
14x29= 406 (slightly too small)
14x29.5= 413
Hope this helps :)