Question

Solve the simultaneous equations by substitution
3y - 2x = -7
5x + 3y = 28

Answer 1

-(3y-2x= -7)

3y+5x= 28

-3y+2x= 7

3y+5x= 28

7x=35

7x/7= 35/7

x=5

5(5)+3y= 28

25+3y=28

3y= 28-25

3y=3

3y/3=3/3

y= 1

3y-2x= -7

3(1) -2x= -7

3-2x= -7

-2x= -7-3

-2x= -10

-2x/-2=-10/-2

x= 5

chekin

5x+3y=28

5(5)+3(1)=28

25+3=28

28=28

Answer 2

(5, 1 )

Explanation:

Given the 2 equations

3y - 2x = - 7 → (1)

5x + 3y = 28 → (2)

Rearrange (1) expressing 3y in terms of x by adding 2x to both sides

3y = - 7 + 2x

Substitute 3y = - 7 + 2x into (2)

5x - 7 + 2x = 28

7x - 7 = 28 ( add 7 to both sides )

7x = 35 ( divide both sides by 7 )

x = 5

Substitute x = 5 into either of the 2 equations and solve for y

Substituting into (2)

5(5) + 3y = 28

25 + 3y = 28 ( subtract 25 from both sides )

3y = 3 ( divide both sides by 3 )

y = 1

solution is (5, 1 )