Question

What is the value of x in the equation 1/5 x-2/3 y=30 when y =15

Answer 1

The answer: x = 200 .
________________________________________________
Step-by-step explanation:
________________________________________________
Given the equation:
________________________________________________
(1/5)x - (2/3)y = 30 ;

What is the value of "x" when "y" = 15 ?
_____________________________________
Plug in "15" for "y" into the equation; and solve:

(1/5)x - (2/3)*15 = 30 ;

Note:
`(2)/(3)*( (15)/(1)) = (2*15)/(3*1) = (30)/(3) = 10 ;`


OR:
[tex] (2)/(1) * (5)/(1) = (2*5)/(1*1) = (10)/(1) = 10 ; " src="


Or: [tex] \frac{2}{1} * \frac{5}{1} = 2 * 5 ; (since 2/1 = 2; and since 5/1 = 6 ;

→ 2 * 5 = 10 ;
______________________________________________________

So, we can rewrite the equation:
_____________________________________________________
(1/5)x - (2/3)y = 30 ; and replace "(2/3)y" with "10") ;

(1/5)x - 10 = 30 ;

Add "10" to EACH SIDE of the equation;

(1/5)x - 10 + 10 = 30 + 10 ;

to get: (1/5)x = 40 ;

Now, multiply EACH SIDE of the equation by "5" ; to isolate "x" on one side of the equation ; and to solve for "x" ;
________________________________________________

5* (1/5)x = 40 * 5 ;

x = 200 ;
______________________________________
The answer: x = 200 .
______________________________________

Answer 2

First replace y with 15.
1/5x-10=30
Then just solve from there.
x=200