Question

6x-2y=10 and 6x+3y=15

Answer 1

x = 2 , y = 1

Explanation:

to solve this simultaneous equation, we say

let

6x - 2y = 10 ..................... equation 1

6x + 3y = 15 ........................ equation 2

using substitution method

from equation 1

6x - 2y = 10 ..................... equation 1

6x = 10 + 2y

divide both sides by 6

x = (10 + 2y)/6 ......................... equation 3

put the value of x in equation 2

6x + 3y = 15 ........................ equation 2

6[( 10 + 2y)/6] + 3y = 15

10 + 2y + 3y = 15

collect the like terms

2y + 3y = 15 - 10

5y = 5

divide both sides by 5

we have

y = 1

put y = 1 in equation 3 to get the value of x

x = (10 + 2y)/6 ......................... equation 3

x = 10 + 2(1) /6

x = 12/6

x = 2

therefore the value of x and y is 2 & 1 respectively

Answer 2

x = 2 ; y =1

Explanation:

6x-2y=10 -----------------(i)

6x+3y=15 -------------(ii)

multiply (i) by (-1)

(i)* (-1) -6x + 2y = -10

(ii) 6x + 3y = 15

add, 5y = 5

y= 5/5

y = 1

Put y = 1 in (i)

6x - 2*1 = 10

6x - 2 = 10

6x = 10 + 2

6x = 12

x = 12/6

x = 2