Question

 

solve the simultaneous equations by an algebraic method.

show all your working

3x+4y=19

4x+5y=23

 

 

Answer 1

line 1: 3x+4y =19

line 2: 4x+5y=23

then x+y=4 (me had nonkontrabel erj tu du that)

or from line1, get y=-(3/4)x +19/4

put this in line1.5...(x+y=4)...x-(3/4)x +19/4 =4

or 4x -3x +19=16

x=16-19=-3

so y=4-x=4+3=7

Answer 2

Please help me solve these simultaneous equations:

2x - 5y = 19

3x + 7y = -15

Comments

You’re answering a question with another question. So I’m answering your question as a comment.

Multiply the first equation by 3 and the second by 2:

6x-15y=57

6x+14y=-30

Subtract the first equation from the second above:

29y=-87, y=-87/29=-3.

Go back to either of the two original equations and substitute y=-3:

2x+15=19, 2x=4, x=2.

SOLUTION: x=2, y=-3 satisfies both equations.