94.0k views
2 votes
Estimate the solution to the system of equations.

-3x+3y=9

2x-7y=-14

1 Answer

3 votes

Answer:

x = 3.89

x = 4............... approximately'

y =6.889

y = 7................ approximately

Explanation:

let

-3x+3y=9 ...................equation 1

2x-7y=-14.................... equation 2

from equation 1

-3x+3y=9 ...................equation 1

3y = 9 + 3x

divide both sides by 3

3y/3 = ( 9 + 3x)/3

y = ( 9 + 3x)/3......................equation 3

put the value of y = ( 9 + 3x)/3 in equation 2

2x-7y=-14.................... equation 2

2x - 7(9+3x)/3 = -14

2x - (63 + 21x)/3 = -14

multiply through by 3

3(2x) - 3 (63 + 21x)/3 = 3(14)

6x - 63 + 21x = 42

collect the like terms -11.667

6x+21x = 42+ 63

27x = 105

divide both sides by 27

x = 105/27

x = 3.89

x = 4............... approximately'

substitute for the value of x in equation 3

y = ( 9 + 3x)/3......................equation 3

y = ( 9 + 3(3.89) )/3

y = (9 + 11.67)/3

y = 20.667/3

y =6.889

y = 7................ approximately

to check for the correctness of your answer put the value of x and y in either equation 1 or equation 2, then u will observe the LHS= RHS

-3x+3y=9 ...................equation 1

-3(3.889) + 3(6.889) = 9

9 = 9 ......................... PROVED

User Mindphaser
by
5.6k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.